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1. Relativity of the event: examples in JT gravity and linearized GR

Author

Francesco Nitti, Federico Piazza, and Alexander Taskov

Subjects
Models of Quantum Gravity, 2D Gravity, Gauge-Gravity Correspondence, Nuclear and particle physics. Atomic energy. Radioactivity, QC770-798
Abstract

Abstract Observables in quantum gravity are famously defined asymptotically, at the boundary of AdS or Minkowski spaces. However, by gauge fixing a coordinate system or suitably dressing the field operators, an approximate, “quasi-local” approach is also possible, that can give account of the measurements performed by a set of observers living inside the spacetime. In particular, one can attach spatial coordinates to the worldlines of these observers and use their proper times as a time coordinate. Here we highlight that any such local formulation has to face the relativity of the event, in that changing frame (= set of observers) implies a reshuffling of the point-events and the way they are identified. As a consequence, coordinate transformations between different frames become probabilistic in quantum gravity. We give a concrete realization of this mechanism in Jackiw-Teitelboim gravity, where a point in the bulk can be defined operationally with geodesics anchored to the boundary. We describe different ways to do so, each corresponding to a different frame, and compute the variances of the transformations relating some of these frames. In particular, we compute the variance of the location of the black hole horizon, which appears smeared in most frames. We then suggest how to calculate this effect in Einstein gravity, assuming knowledge of the wavefunction of the metric. The idea is to expand the latter on a basis of semiclassical states. Each element of this basis enjoys standard/deterministic coordinate transformations and the result is thus obtained by superposition. As a divertissement, we sabotage Lorentz boosts by adding to Minkoswki space a quantum superposition of gravitational waves and compute the probabilistic coordinate transformation to a boosted frame at linear order. Finally, we attempt to translate the relativity of the event into the language of dressed operators.

Published
2024
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2. Quantum (in)stability of maximally symmetric space-times

Author

Jewel K. Ghosh, Elias Kiritsis, Francesco Nitti, and Valentin Nourry

Subjects
AdS-CFT Correspondence, Effective Field Theories, Field Theories in Higher Dimensions, Gauge-Gravity Correspondence, Nuclear and particle physics. Atomic energy. Radioactivity, QC770-798
Abstract

Abstract Classical gravity coupled to a CFT4 (matter) is considered. The effect of the quantum dynamics of matter on gravity is studied around maximally symmetric spaces (flat, de Sitter and Anti de Sitter). The structure of the graviton propagator is modified and non-trivial poles appear due to matter quantum effects. The position and residues of such poles are mapped as a function of the relevant parameters, the central charge of the CFT4, the two R 2 couplings of gravity as well as the curvature of the background space-time. The instabilities induced are determined. Such instabilities can be important in cosmology as they trigger the departure from de Sitter space and in some regions of parameters are more important than the well-known scalar instabilities. It is also determined when the presence of such instabilities is unreliable if the associated scales are larger than the “species” cutoff of the gravitational theory.

Published
2023
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3. Holographic CFTs on AdS d × S n and conformal defects

Author

Ahmad Ghodsi, Elias Kiritsis, and Francesco Nitti

Subjects
Field Theories in Higher Dimensions, Gauge-Gravity Correspondence, Nuclear and particle physics. Atomic energy. Radioactivity, QC770-798
Abstract

Abstract We consider (d+n+1)-dimensional solutions of Einstein gravity with constant negative curvature. Regular solutions of this type are expected to be dual to the ground states of (d + n)-dimensional holographic CFTs on AdS d × S n . Their only dimensionless parameter is the ratio of radii of curvatures of AdS d and S n . The same solutions may also be dual to (d − 1)-dimensional conformal defects in holographic QFT d+n . We solve the gravity equations with an associated conifold ansatz, and we classify all solutions both singular and regular by a combination of analytical and numerical techniques. There are no solutions, regular or singular, with two boundaries along the holographic direction. Out of the infinite class of regular solutions, only one is diffeomorphic to AdS d+n+1 and another to AdS d × AdS n+1. For the regular solutions, we compute the on-shell action as a function of the relevant parameters.

Published
2023
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4. Flavored ABJM theory on the sphere and holographic F-functions

Author

Niko Jokela, Jani Kastikainen, Elias Kiritsis, and Francesco Nitti

Subjects
AdS-CFT Correspondence, D-Branes, Renormalization Group, Nuclear and particle physics. Atomic energy. Radioactivity, QC770-798
Abstract

Abstract We study strongly coupled ABJM theory on the 3-sphere with massive quenched flavor using the AdS/CFT correspondence. The holographic dual consists of type IIA supergravity with probe D6-branes. The flavor mass is a relevant deformation driving an RG flow whose IR endpoint is pure ABJM theory. At non-zero mass, we find that the theory on the 3-sphere exhibits a quantum phase transition at a critical value of the sphere radius. The transition corresponds to a topology change in the D6-brane embeddings whose dual interpretation is the meson-melting transition. We perform the holographic computation of the free energy on 3-sphere and we use it to construct various candidate F-functions. These were recently proposed in the context of Einstein-scalar gravity to interpolate monotonically between the values of the sphere free energies of the UV and IR CFTs. We find that while the F-functions of the flavored ABJM theory have the correct UV and IR limits, they are not monotonic. We surmise that the non-monotonicity is related to the presence of the phase transition.

Published
2022
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5. Revisiting Coleman-de Luccia transitions in the AdS regime using holography

Author

Jewel K. Ghosh, Elias Kiritsis, Francesco Nitti, and Lukas T. Witkowski

Subjects
AdS-CFT Correspondence, Nonperturbative Effects, Nuclear and particle physics. Atomic energy. Radioactivity, QC770-798
Abstract

Abstract Coleman-de Luccia processes for AdS to AdS decays in Einstein-scalar theories are studied. Such tunnelling processes are interpreted as vev-driven holographic RG flows of a quantum field theory on de Sitter space-time. These flows do not exist for generic scalar potentials, which is the holographic formulation of the fact that gravity can act to stabilise false AdS vacua. The existence of Coleman-de Luccia tunnelling solutions in a potential with a false AdS vacuum is found to be tied to the existence of exotic RG flows in the same potential. Such flows are solutions where the flow skips possible fixed points or reverses direction in the coupling. This connection is employed to construct explicit potentials that admit Coleman-de Luccia instantons in AdS and to study the associated tunnelling solutions. Thin-walled instantons are observed to correspond to dual field theories with a parametrically large value of the dimension ∆ for the operator dual to the scalar field, casting doubt on the attainability of this regime in holography. From the boundary perspective, maximally symmetric instantons describe the probability of symmetry breaking of the dual QFT in de Sitter. It is argued that, even when such instantons exist, they do not imply an instability of the same theory on flat space or on R × S 3.

Published
2021
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6. Holographic QFTs on S2 ×S2, spontaneous symmetry breaking and Efimov saddle points

Author

Elias Kiritsis, Francesco Nitti, and Edwan Préau

Subjects
AdS-CFT Correspondence, Conformal Field Theory, Gauge-gravity correspondence, Renormalization Group, Nuclear and particle physics. Atomic energy. Radioactivity, QC770-798
Abstract

Abstract Holographic CFTs and holographic RG flows on space-time manifolds which are d-dimensional products of spheres are investigated. On the gravity side, this corresponds to Einstein-dilaton gravity on an asymptotically AdS d+1 geometry, foliated by a product of spheres. We focus on holographic theories on S 2 × S 2, we show that the only regular five-dimensional bulk geometries have an IR endpoint where one of the sphere shrinks to zero size, while the other remains finite. In the Z 2-symmetric limit, where the two spheres have the same UV radii, we show the existence of a infinite discrete set of regular solutions, satisfying an Efimov-like discrete scaling. The Z 2-symmetric solution in which both spheres shrink to zero at the endpoint is singular, whereas the solution with lowest free energy is regular and breaks Z 2 symmetry spontaneously. We explain this phenomenon analytically by identifying an unstable mode in the bulk around the would-be Z 2-symmetric solution. The space of theories have two branches that are connected by a conifold transition in the bulk, which is regular and correspond to a quantum first order transition. Our results also imply that AdS 5 does not admit a regular slicing by S 2 × S 2.

Published
2020
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7. Exotic holographic RG flows at finite temperature

Author

Umut Gürsoy, Elias Kiritsis, Francesco Nitti, and Leandro Silva Pimenta

Subjects
AdS-CFT Correspondence, Black Holes, Gauge-gravity correspondence, Nuclear and particle physics. Atomic energy. Radioactivity, QC770-798
Abstract

Abstract Black hole solutions and their thermodynamics are studied in Einstein-scalar theories. The associated zero-temperature solutions are non-trivial holographic RG flows. These include solutions which skip intermediate extrema of the bulk scalar potential or feature an inversion of the direction of the flow of the coupling (bounces). At finite temperature, a complex set of branches of black hole solutions is found. In some cases, first order phase transitions are found between the black-hole branches. In other cases, black hole solutions are found to exist even for boundary conditions which did not allow a zero-temperature vacuum flow. Finite-temperature solutions driven solely by the vacuum expectation value of a perturbing operator (zero source) are found and studied. Such solutions exist generically (i.e. with no special tuning of the potential) in theories in which the vacuum flows feature bounces. It is found that they exhibit conformal thermodynamics.

Published
2018
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8. On multi-field flows in gravity and holography

Author

Francesco Nitti, Leandro Silva Pimenta, and Danièle A. Steer

Subjects
AdS-CFT Correspondence, Gauge-gravity correspondence, Nuclear and particle physics. Atomic energy. Radioactivity, QC770-798
Abstract

Abstract We perform a systematic analysis of flow-like solutions in theories of Einstein gravity coupled to multiple scalar fields, which arise as holographic RG flows as well as in the context of cosmological solutions driven by scalars. We use the first order formalism and the superpotential formulation to classify solutions close to generic extrema of the scalar potential, and close to “bounces,” where the flow is inverted in some or all directions and the superpotential becomes multi-valued. Although the superpotential formulation contains a large redundancy, we show how this can be completely lift by suitable regularity conditions. We place the first order formalism in the context of Hamilton-Jacobi theory, where we discuss the possibility of non-gradient flows and their connection to non-separable solutions of the Hamilton-Jacobi equation. We argue that non-gradient flows may be useful in the presence of global symmetries in the scalar sector.

Published
2018
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9. Holographic self-tuning of the cosmological constant

Author

Christos Charmousis, Elias Kiritsis, and Francesco Nitti

Subjects
Gauge-gravity correspondence, Large Extra Dimensions, Nuclear and particle physics. Atomic energy. Radioactivity, QC770-798
Abstract

Abstract We propose a brane-world setup based on gauge/gravity duality in which the four-dimensional cosmological constant is set to zero by a dynamical self-adjustment mechanism. The bulk contains Einstein gravity and a scalar field. We study holographic RG flow solutions, with the standard model brane separating an infinite volume UV region and an IR region of finite volume. For generic values of the brane vacuum energy, regular solutions exist such that the four-dimensional brane is flat. Its position in the bulk is determined dynamically by the junction conditions. Analysis of linear fluctuations shows that a regime of 4-dimensional gravity is possible at large distances, due to the presence of an induced gravity term. The graviton acquires an effective mass, and a five-dimensional regime may exist at large and/or small scales. We show that, for a broad choice of potentials, flat-brane solutions are manifestly stable and free of ghosts. We compute the scalar contribution to the force between brane-localized sources and show that, in certain models, the vDVZ discontinuity is absent and the effective interaction at short distances is mediated by two transverse graviton helicities.

Published
2017
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10. Flavored ABJM theory on the sphere and holographic F-functions

Author

Niko Jokela, Jani Kastikainen, Elias Kiritsis, Francesco Nitti, AstroParticule et Cosmologie (APC (UMR_7164)), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Observatoire de Paris, Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Centre National de la Recherche Scientifique (CNRS)-Université de Paris (UP), Helsinki Institute of Physics, Department of Physics, and Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Centre National de la Recherche Scientifique (CNRS)-Université Paris Cité (UPCité)

Subjects
High Energy Physics - Theory, topology: transition, Nuclear and High Energy Physics, AdS/CFT correspondence, [PHYS.HTHE]Physics [physics]/High Energy Physics - Theory [hep-th], FOS: Physical sciences, critical phenomena, AdS-CFT Correspondence, 114 Physical sciences, free energy, supergravity: Type IIA, D-Branes, SUPERSYMMETRIC DOMAIN-WALL, High Energy Physics - Theory (hep-th), renormalization group: flow, Renormalization Group, D-brane: 6, sphere: 3, ABJM model
Abstract

We study strongly coupled ABJM theory on the 3-sphere with massive quenched flavor using the AdS/CFT correspondence. The holographic dual consists of type IIA supergravity with probe D6-branes. The flavor mass is a relevant deformation driving an RG flow whose IR endpoint is pure ABJM theory. At non-zero mass, we find that the theory on the 3-sphere exhibits a quantum phase transition at a critical value of the sphere radius. The transition corresponds to a topology change in the D6-brane embeddings whose dual interpretation is the meson-melting transition. We perform the holographic computation of the free energy on 3-sphere and we use it to construct various candidate F-functions. These were recently proposed in the context of Einstein-scalar gravity to interpolate monotonically between the values of the sphere free energies of the UV and IR CFTs. We find that while the F-functions of the flavored ABJM theory have the correct UV and IR limits, they are not monotonic. We surmise that the non-monotonicity is related to the presence of the phase transition., Comment: 52 pages, 9 figures, v3 includes three new references and small corrections, matches the published version

Published
2021
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11. Holographic QFTs on S2×S2, spontaneous symmetry breaking and Efimov saddle points

Author

Edwan Preau, Francesco Nitti, Elias Kiritsis, AstroParticule et Cosmologie (APC (UMR_7164)), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Observatoire de Paris, Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Centre National de la Recherche Scientifique (CNRS)-Université de Paris (UP), Laboratoire de physique de l'ENS - ENS Paris (LPENS (UMR_8023)), École normale supérieure - Paris (ENS Paris), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Centre National de la Recherche Scientifique (CNRS)-Sorbonne Université (SU)-Université Paris Diderot - Paris 7 (UPD7), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Centre National de la Recherche Scientifique (CNRS)-Université Paris Cité (UPCité), École normale supérieure - Paris (ENS-PSL), and Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Université Paris Diderot - Paris 7 (UPD7)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS)

Subjects
dimension: 5, Nuclear and High Energy Physics, Spontaneous symmetry breaking, AdS-CFT Correspondence, Space (mathematics), 01 natural sciences, Gauge-gravity correspondence, scaling: discrete, conifold: transition, Saddle point, 0103 physical sciences, lcsh:Nuclear and particle physics. Atomic energy. Radioactivity, Renormalization Group, 010306 general physics, Scaling, Mathematical physics, field theory: conformal, [PHYS]Physics [physics], Physics, Conformal Field Theory, Conifold, [PHYS.HTHE]Physics [physics]/High Energy Physics - Theory [hep-th], 010308 nuclear & particles physics, Conformal field theory, symmetry breaking: Z(2), free energy, Symmetry (physics), AdS/CFT correspondence, renormalization group: flow, lcsh:QC770-798, holography, gravitation: dilaton, AdS(5), [PHYS.ASTR]Physics [physics]/Astrophysics [astro-ph]
Abstract

Holographic CFTs and holographic RG flows on space-time manifolds which are d-dimensional products of spheres are investigated. On the gravity side, this corresponds to Einstein-dilaton gravity on an asymptotically AdSd+1 geometry, foliated by a product of spheres. We focus on holographic theories on S2× S2, we show that the only regular five-dimensional bulk geometries have an IR endpoint where one of the sphere shrinks to zero size, while the other remains finite. In the Z2-symmetric limit, where the two spheres have the same UV radii, we show the existence of a infinite discrete set of regular solutions, satisfying an Efimov-like discrete scaling. The Z2-symmetric solution in which both spheres shrink to zero at the endpoint is singular, whereas the solution with lowest free energy is regular and breaks Z2 symmetry spontaneously. We explain this phenomenon analytically by identifying an unstable mode in the bulk around the would-be Z2-symmetric solution. The space of theories have two branches that are connected by a conifold transition in the bulk, which is regular and correspond to a quantum first order transition. Our results also imply that AdS5 does not admit a regular slicing by S2× S2.

Published
2020
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12. Holographic theories at finite $\theta$-angle, CP-violation, glueball spectra and strong-coupling instabilities

Author

Francesco Nitti, Elias Kiritsis, Yuta Hamada, AstroParticule et Cosmologie (APC (UMR_7164)), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Observatoire de Paris, Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Centre National de la Recherche Scientifique (CNRS)-Université de Paris (UP), and Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Centre National de la Recherche Scientifique (CNRS)-Université Paris Cité (UPCité)

Subjects
High Energy Physics - Theory, Particle physics, Instanton, Field (physics), High Energy Physics::Lattice, Holography, General Physics and Astronomy, instanton: density, glueball: mass, 03 medical and health sciences, High Energy Physics::Theory, High Energy Physics - Lattice, Instanton density, strong coupling, CP: violation, ground state, Axion, 030304 developmental biology, Physics, Quantum chromodynamics, 0303 health sciences, Glueball, [PHYS.HTHE]Physics [physics]/High Energy Physics - Theory [hep-th], [PHYS.HLAT]Physics [physics]/High Energy Physics - Lattice [hep-lat], Operator (physics), 030302 biochemistry & molecular biology, stability, Theta-angle, duality: holography, QCD, instability, High Energy Physics - Phenomenology, axion, [PHYS.HPHE]Physics [physics]/High Energy Physics - Phenomenology [hep-ph], glueballs, CP violation, Dilaton, High Energy Physics::Experiment, strong CP-violation, dilaton: potential
Abstract

A general class of holographic theories with a nontrivial $\theta$-angle are analyzed. The instanton density operator is dual to a bulk axion field. We calculate the ground-state solutions with nontrivial source, $a_{UV}$, for the axion, for both steep and soft dilaton potentials in the IR, and both in $d=3$ and $d=4$. We find all cases to be qualitatively similar. We also calculate the spin$=2,0$ glueball spectra and show that the glueball masses monotonically decrease as functions of $a_{UV}$ (or $\theta$-angle). The slopes of glueball masses are different, generically, in different potentials. In the case of steep dilaton potentials, the glueball (masses)$^2$ turn negative before the maximum of $a_{UV}$ is attained. We interpret this as a signal for a favored instanton condensation in the bulk. We also investigate strong CP-violation in the effective glueball action., Comment: 70 pages, 25 figures; minor changes (v2)

Published
2020
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13. Back-reaction in massless de Sitter QFTs: holography, gravitational DBI action and f(R) gravity

Author

Lukas T. Witkowski, Elias Kiritsis, Jewel Kumar Ghosh, Francesco Nitti, AstroParticule et Cosmologie (APC (UMR_7164)), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Observatoire de Paris, Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Centre National de la Recherche Scientifique (CNRS)-Université de Paris (UP), Institut d'Astrophysique de Paris (IAP), Institut national des sciences de l'Univers (INSU - CNRS)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS), and Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Centre National de la Recherche Scientifique (CNRS)-Université Paris Cité (UPCité)

Subjects
High Energy Physics - Theory, partition function, FOS: Physical sciences, General Relativity and Quantum Cosmology (gr-qc), Einstein manifold, Cosmological constant, 01 natural sciences, General Relativity and Quantum Cosmology, Gravitation, De Sitter universe, 0103 physical sciences, space-time: de Sitter, Born-Infeld model: action, Quantum field theory, 010306 general physics, Effective action, Mathematical physics, Holographic principle, Physics, field theory: conformal, cosmological constant, 010308 nuclear & particles physics, [PHYS.HTHE]Physics [physics]/High Energy Physics - Theory [hep-th], Astronomy and Astrophysics, back reaction, duality: holography, ultraviolet infrared, gravitation: f(R), High Energy Physics - Theory (hep-th), [PHYS.GRQC]Physics [physics]/General Relativity and Quantum Cosmology [gr-qc], f(R) gravity, expansion 1/N
Abstract

We employ gauge-gravity duality to study the backreaction effect of 4-dimensional large-$N$ quantum field theories on constant-curvature backgrounds, and in particular de Sitter space-time. The field theories considered are holographic QFTs, dual to RG flows between UV and IR CFTs. We compute the holographic QFT contribution to the gravitational effective action for 4d Einstein manifold backgrounds. We find that for a given value of the cosmological constant $\lambda$, there generically exist two backreacted constant-curvature solutions, as long as $\lambda < \lambda_{\textrm{max}} \sim M_p^2 / N^2$, otherwise no such solutions exist. Moreover, the backreaction effect interpolates between that of the UV and IR CFTs. We also find that, at finite cutoff, a holographic theory always reduces the bare cosmological constant, and this is the consequence of thermodynamic properties of the partition function of holographic QFTs on de Sitter., Comment: 65 pages + appendices, 10 figures, executive summary in the introduction

Published
2020
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14. Holographic RG flows on curved manifolds and the F-theorem

Author

Elias Kiritsis, Jewel Kumar Ghosh, Francesco Nitti, Lukas T. Witkowski, AstroParticule et Cosmologie (APC (UMR_7164)), Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Centre National de la Recherche Scientifique (CNRS)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Observatoire de Paris, PSL Research University (PSL)-PSL Research University (PSL)-Université Paris Diderot - Paris 7 (UPD7), Observatoire de Paris, Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Paris Diderot - Paris 7 (UPD7)-Centre National de la Recherche Scientifique (CNRS)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3), PSL Research University (PSL)-PSL Research University (PSL)-Université Paris Diderot - Paris 7 (UPD7)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Centre National de la Recherche Scientifique (CNRS), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Observatoire de Paris, and Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Université Paris Diderot - Paris 7 (UPD7)-Centre National de la Recherche Scientifique (CNRS)

Subjects
High Energy Physics - Theory, Nuclear and High Energy Physics, Holography, FOS: Physical sciences, Monotonic function, Quantum entanglement, AdS-CFT Correspondence, 01 natural sciences, law.invention, Legendre transformation, symbols.namesake, law, 0103 physical sciences, entropy: entanglement, surface, Entropy (information theory), lcsh:Nuclear and particle physics. Atomic energy. Radioactivity, Renormalization Group, on-shell, 010306 general physics, Quantum, Mathematical physics, Boson, Physics, [PHYS.HTHE]Physics [physics]/High Energy Physics - Theory [hep-th], 010308 nuclear & particles physics, effective potential, operator: dimension, Fermion, duality: holography, S(3), free energy, High Energy Physics - Theory (hep-th), renormalization group: flow, symbols, lcsh:QC770-798
Abstract

We study $F$-functions in the context of field theories on $S^3$ using gauge-gravity duality, with the radius of $S^3$ playing the role of RG scale. We show that the on-shell action, evaluated over a set of holographic RG flow solutions, can be used to define good $F$-functions, which decrease monotonically along the RG flow from the UV to the IR for a wide range of examples. If the operator perturbing the UV CFT has dimension $\Delta > 3/2$ these $F$-functions correspond to an appropriately renormalized free energy. If instead the perturbing operator has dimension $\Delta < 3/2$ it is the quantum effective potential, i.e. the Legendre transform of the free energy, which gives rise to good $F$-functions. We check that these observations hold beyond holography for the case of a free fermion on $S^3$ ($\Delta=2$) and the free boson on $S^3$ ($\Delta=1$), resolving a long-standing problem regarding the non-monotonicity of the free energy for the free massive scalar. We also show that for a particular choice of entangling surface, we can define good $F$-functions from an entanglement entropy, which coincide with certain $F$-functions obtained from the on-shell action., Comment: 83 pages, 12 figures

Published
2019
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15. Axion RG flows and the holographic dynamics of instanton densities

Author

Lukas T. Witkowski, Yuta Hamada, Francesco Nitti, Elias Kiritsis, AstroParticule et Cosmologie (APC (UMR_7164)), Observatoire de Paris, PSL Research University (PSL)-PSL Research University (PSL)-Université Paris Diderot - Paris 7 (UPD7)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Centre National de la Recherche Scientifique (CNRS), Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Centre National de la Recherche Scientifique (CNRS)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Observatoire de Paris, PSL Research University (PSL)-PSL Research University (PSL)-Université Paris Diderot - Paris 7 (UPD7), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Paris Diderot - Paris 7 (UPD7)-Centre National de la Recherche Scientifique (CNRS)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Observatoire de Paris, and Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Université Paris Diderot - Paris 7 (UPD7)-Centre National de la Recherche Scientifique (CNRS)

Subjects
Statistics and Probability, High Energy Physics - Theory, Instanton, Physics::Instrumentation and Detectors, General Physics and Astronomy, FOS: Physical sciences, Context (language use), Conformal map, instanton: density, Fixed point, 01 natural sciences, expansion 1/N: color, Theoretical physics, High Energy Physics::Theory, High Energy Physics - Phenomenology (hep-ph), 0103 physical sciences, Limit (mathematics), 010306 general physics, numerical calculations, Axion, Mathematical Physics, Physics, 010308 nuclear & particles physics, [PHYS.HTHE]Physics [physics]/High Energy Physics - Theory [hep-th], Operator (physics), High Energy Physics::Phenomenology, Statistical and Nonlinear Physics, back reaction, High Energy Physics - Phenomenology, Flow (mathematics), effective action, High Energy Physics - Theory (hep-th), Modeling and Simulation, fixed point: conformal, axion, [PHYS.HPHE]Physics [physics]/High Energy Physics - Phenomenology [hep-ph], renormalization group: flow, gravitation: dilaton, holography
Abstract

Axionic holographic RG flow solutions are studied in the context of general Einstein-Axion-Dilaton theories. A non-trivial axion profile is dual to the (non-perturbative) running of the $\theta$-term for the corresponding instanton density operator. It is shown that a non-trivial axion solution is incompatible with a non-trivial (holographic) IR conformal fixed point. Imposing a suitable axion regularity condition allows to select the IR geometry in a unique way. The solutions are found analytically in the asymptotic UV and IR regimes, and it is shown that in those regimes the axion backreaction is always negligible. The axion backreaction may become important in the intermediate region of the bulk. To make contact with the axion probe limit solutions, a systematic expansion of the solution is developed. Several concrete examples are worked out numerically. It is shown that the regularity condition always implies a finite allowed range for the axion source parameter in the UV. This translates into the existence of a finite (but large) number of saddle-points in the large $N_c$ limit. This ties in well with axion-swampland conjectures., Comment: 60 pages, 11 figures

Published
2019
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16. Brane cosmology and the self-tuning of the cosmological constant

Author

Christos Charmousis, Elias Kiritsis, Francesco Nitti, D. Forcella, A. Amariti, Laboratoire de Physique Théorique d'Orsay [Orsay] (LPT), Université Paris-Sud - Paris 11 (UP11)-Centre National de la Recherche Scientifique (CNRS), AstroParticule et Cosmologie (APC (UMR_7164)), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Observatoire de Paris, Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Université Paris Diderot - Paris 7 (UPD7)-Centre National de la Recherche Scientifique (CNRS), Observatoire de Paris, PSL Research University (PSL)-PSL Research University (PSL)-Université Paris Diderot - Paris 7 (UPD7)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Centre National de la Recherche Scientifique (CNRS), Centre National de la Recherche Scientifique (CNRS)-Université Paris-Sud - Paris 11 (UP11), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Paris Diderot - Paris 7 (UPD7)-Centre National de la Recherche Scientifique (CNRS)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3), Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Centre National de la Recherche Scientifique (CNRS)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Observatoire de Paris, and PSL Research University (PSL)-PSL Research University (PSL)-Université Paris Diderot - Paris 7 (UPD7)

Subjects
High Energy Physics - Theory, cosmological model, gravitation: model, media_common.quotation_subject, Coordinate system, FOS: Physical sciences, Cosmological constant, General Relativity and Quantum Cosmology (gr-qc), Astrophysics::Cosmology and Extragalactic Astrophysics, 01 natural sciences, General Relativity and Quantum Cosmology, Cosmology, membrane model, Theoretical physics, High Energy Physics - Phenomenology (hep-ph), De Sitter universe, de Sitter, 0103 physical sciences, Brane cosmology, Limit (mathematics), modified gravity, media_common, Physics, cosmological constant, 010308 nuclear & particles physics, [PHYS.HTHE]Physics [physics]/High Energy Physics - Theory [hep-th], Astronomy and Astrophysics, Universe, High Energy Physics - Phenomenology, High Energy Physics - Theory (hep-th), field equations: solution, [PHYS.HPHE]Physics [physics]/High Energy Physics - Phenomenology [hep-ph], brane cosmology, [PHYS.GRQC]Physics [physics]/General Relativity and Quantum Cosmology [gr-qc], holography, Brane
Abstract

The cosmology of branes undergoing the self-tuning mechanism of the cosmological constant is considered. The equations and matching conditions are derived in several coordinate systems, and an exploration of possible solution strategies is performed. The ensuing equations are solved analytically in the probe brane limit. We classify the distinct behavior for the brane cosmology and we correlate them with properties of the bulk (static) solutions. Their matching to the actual universe cosmology is addressed., Comment: 44 pages + appendix, 1 figure

Published
2019
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17. De Sitter and Anti-de Sitter branes in self-tuning models

Author

Jewel Kumar Ghosh, Francesco Nitti, Lukas T. Witkowski, Elias Kiritsis, AstroParticule et Cosmologie (APC (UMR_7164)), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Observatoire de Paris, Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Centre National de la Recherche Scientifique (CNRS)-Université de Paris (UP), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Centre National de la Recherche Scientifique (CNRS)-Université Paris Cité (UPCité), Observatoire de Paris, PSL Research University (PSL)-PSL Research University (PSL)-Université Paris Diderot - Paris 7 (UPD7)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Centre National de la Recherche Scientifique (CNRS), Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Centre National de la Recherche Scientifique (CNRS)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Observatoire de Paris, and PSL Research University (PSL)-PSL Research University (PSL)-Université Paris Diderot - Paris 7 (UPD7)

Subjects
High Energy Physics - Theory, Nuclear and High Energy Physics, geometry, dimension: 4, De Sitter space, FOS: Physical sciences, General Relativity and Quantum Cosmology (gr-qc), hierarchy, AdS-CFT Correspondence, field theory, String theory, Curvature, 01 natural sciences, General Relativity and Quantum Cosmology, Gauge-gravity correspondence, vacuum state, High Energy Physics::Theory, High Energy Physics - Phenomenology (hep-ph), de Sitter, membrane model: stability, De Sitter universe, 0103 physical sciences, anti-de Sitter, Brane cosmology, lcsh:Nuclear and particle physics. Atomic energy. Radioactivity, 010306 general physics, Mathematical physics, field theory: conformal, Physics, cosmological constant, [PHYS.HTHE]Physics [physics]/High Energy Physics - Theory [hep-th], 010308 nuclear & particles physics, duality: holography, High Energy Physics - Phenomenology, AdS/CFT correspondence, High Energy Physics - Theory (hep-th), curvature, [PHYS.HPHE]Physics [physics]/High Energy Physics - Phenomenology [hep-ph], [PHYS.GRQC]Physics [physics]/General Relativity and Quantum Cosmology [gr-qc], lcsh:QC770-798, Anti-de Sitter space, Brane
Abstract

Maximally symmetric curved-brane solutions are studied in dilatonic braneworld models which realise the self-tuning of the effective four-dimensional cosmological constant. It is found that no vacua in which the brane has de Sitter or anti-de Sitter geometry exist, unless one modifies the near-boundary asymptotics of the bulk fields. In the holographic dual picture, this corresponds to coupling the UV CFT to a curved metric (possibly with a defect). Alternatively, the same may be achieved in a flat-space QFT with suitable variable scalar sources. With these ingredients, it is found that maximally symmetric, positive and negative curvature solutions with a stabilised brane position generically exist. The space of such solutions is studied in two different types of realisations of the self-tuning framework. In some regimes we observe a large hierarchy between the curvature on the brane and the boundary UV CFT curvature. This is a dynamical effect due to the self-stabilisation mechanism. This setup provides an alternative route to realising de Sitter space in string theory., Comment: 55 pages, 18 figures; v2: references added, minor typos corrected, a few clarifications added, matches the published version

Published
2018
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18. On multi-field flows in gravity and holography

Author

Leandro Silva Pimenta, Daniele A. Steer, Francesco Nitti, AstroParticule et Cosmologie (APC (UMR_7164)), Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Centre National de la Recherche Scientifique (CNRS)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Observatoire de Paris, PSL Research University (PSL)-PSL Research University (PSL)-Université Paris Diderot - Paris 7 (UPD7), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Observatoire de Paris, Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Centre National de la Recherche Scientifique (CNRS)-Université de Paris (UP), Observatoire de Paris, PSL Research University (PSL)-PSL Research University (PSL)-Université Paris Diderot - Paris 7 (UPD7)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Centre National de la Recherche Scientifique (CNRS), and Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Centre National de la Recherche Scientifique (CNRS)-Université Paris Cité (UPCité)

Subjects
High Energy Physics - Theory, Nuclear and High Energy Physics, Scalar (mathematics), Holography, FOS: Physical sciences, Scalar potential, AdS-CFT Correspondence, superpotential, 01 natural sciences, symmetry: global, Gauge-gravity correspondence, law.invention, Theoretical physics, symbols.namesake, General Relativity and Quantum Cosmology, law, 0103 physical sciences, lcsh:Nuclear and particle physics. Atomic energy. Radioactivity, gravitation: coupling, Einstein, 010306 general physics, Physics, 010308 nuclear & particles physics, [PHYS.HTHE]Physics [physics]/High Energy Physics - Theory [hep-th], Superpotential, potential: scalar, field theory: scalar, Maxima and minima, AdS/CFT correspondence, High Energy Physics - Theory (hep-th), bounce, Homogeneous space, symbols, Hamilton-Jacobi equation: solution, renormalization group: flow, lcsh:QC770-798, holography
Abstract

We perform a systematic analysis of flow-like solutions in theories of Einstein gravity coupled to multiple scalar fields, which arise as holographic RG flows as well as in the context of cosmological solutions driven by scalars. We use the first order formalism and the superpotential formulation to classify solutions close to generic extrema of the scalar potential, and close to "bounces," where the flow is inverted in some or all directions and the superpotential becomes multi-valued. Although the superpotential formulation contains a large redundancy, we show how this can be completely lift by suitable regularity conditions. We place the first order formalism in the context of Hamilton-Jacobi theory, where we discuss the possibility of non-gradient flows and their connection to non-separable solutions of the Hamilton-Jacobi equation. We argue that non-gradient flows may be useful in the presence of global symmetries in the scalar sector., 57 pages, 8 figures

Published
2018
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19. Holographic RG flows on curved manifolds and quantum phase transitions

Author

Jewel Kumar Ghosh, Francesco Nitti, Lukas T. Witkowski, Elias Kiritsis, AstroParticule et Cosmologie (APC (UMR_7164)), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Observatoire de Paris, Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Centre National de la Recherche Scientifique (CNRS)-Université de Paris (UP), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Centre National de la Recherche Scientifique (CNRS)-Université Paris Cité (UPCité), Observatoire de Paris, PSL Research University (PSL)-PSL Research University (PSL)-Université Paris Diderot - Paris 7 (UPD7)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Centre National de la Recherche Scientifique (CNRS), Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Centre National de la Recherche Scientifique (CNRS)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Observatoire de Paris, and PSL Research University (PSL)-PSL Research University (PSL)-Université Paris Diderot - Paris 7 (UPD7)

Subjects
Quantum phase transition, High Energy Physics - Theory, Nuclear and High Energy Physics, Phase transition, Critical phenomena, Scalar (mathematics), FOS: Physical sciences, AdS-CFT Correspondence, Curvature, field theory, 01 natural sciences, Gauge-gravity correspondence, beta function, 0103 physical sciences, lcsh:Nuclear and particle physics. Atomic energy. Radioactivity, ground state, Renormalization Group, any-dimensional, 010306 general physics, Mathematical physics, Physics, 010308 nuclear & particles physics, [PHYS.HTHE]Physics [physics]/High Energy Physics - Theory [hep-th], critical phenomena, Renormalization group, duality: holography, AdS/CFT correspondence, High Energy Physics - Theory (hep-th), curvature, renormalization group: flow, lcsh:QC770-798, Dilaton, gravitation: dilaton
Abstract

Holographic RG flows dual to QFTs on maximally symmetric curved manifolds (dS$_d$, AdS$_d$, and $S^d$) are considered in the framework of Einstein-dilaton gravity in $d+1$ dimensions. A general dilaton potential is used and the flows are driven by a scalar relevant operator. The general properties of such flows are analyzed and the UV and IR asymptotics computed. New RG flows can appear at finite curvature which do not have a zero curvature counterpart. The so-called 'bouncing flows', where the $\beta$-function has a branch cut at which it changes sign, are found to persist at finite curvature. Novel quantum first-order phase transitions are found, triggered by a variation in the $d$-dimensional curvature in theories allowing multiple ground states., Comment: 57 pages + appendices, 32 figures; v2: references added, clarifications added in sec. 6.2; v3: section 4.5 on perturbative stability added, section 5.2 on the holographic beta function added, references added

Published
2017
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21. On massless 4D gravitons from asymptotically space–times

Author

Francesco Nitti and Elias Kiritsis

Subjects
Physics, Nuclear and High Energy Physics, 010308 nuclear & particles physics, Scalar (mathematics), Graviton, Duality (optimization), Boundary (topology), Space (mathematics), 01 natural sciences, Massless particle, High Energy Physics::Theory, General Relativity and Quantum Cosmology, Quantum electrodynamics, 0103 physical sciences, Dilaton, Boundary value problem, 010306 general physics, Mathematical physics
Abstract

We investigate the conditions for obtaining four-dimensional massless spin-2 states in the spectrum of fluctuations around an asymptotically AdS 5 solution of Einstein–Dilaton gravity. We find it is only possible to have normalizable massless spin-2 modes if the space–time terminates at some IR point in the extra dimension, far from the UV AdS boundary, and if suitable boundary conditions are imposed at the “end of space”. In some of these cases the 4D spectrum consists only of a massless spin-2 graviton, with no additional massless or light scalar or vector modes. These spin-2 modes have a profile wave-function peaked in the interior of the 5D bulk space–time. Under the holographic duality, they may be sometimes interpreted as arising purely from the IR dynamics of a strongly coupled QFT living on the AdS boundary.

Published
2007
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22. On the gluonic operator effective potential in holographic Yang-Mills theory

Author

Elias Kiritsis, Francesco Nitti, Wenliang Li, AstroParticule et Cosmologie (APC (UMR_7164)), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Observatoire de Paris, Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Université Paris Diderot - Paris 7 (UPD7)-Centre National de la Recherche Scientifique (CNRS), Observatoire de Paris, Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Paris Diderot - Paris 7 (UPD7)-Centre National de la Recherche Scientifique (CNRS)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3), Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Centre National de la Recherche Scientifique (CNRS)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Observatoire de Paris, and PSL Research University (PSL)-PSL Research University (PSL)-Université Paris Diderot - Paris 7 (UPD7)

Subjects
High Energy Physics - Theory, Physics, Quantum chromodynamics, [PHYS]Physics [physics], Nuclear and High Energy Physics, Glueball, Conformal anomaly, High Energy Physics::Lattice, Scalar (mathematics), Holography, FOS: Physical sciences, Yang–Mills theory, Gluon, law.invention, Theoretical physics, Formalism (philosophy of mathematics), High Energy Physics - Theory (hep-th), law, [PHYS.ASTR]Physics [physics]/Astrophysics [astro-ph], ComputingMilieux_MISCELLANEOUS
Abstract

The holographic formalism is applied to the calculation of the effective potential for the scalar glueball operator. Three different versions of this operator are defined, and for each we compute the associated effective potential and discuss its properties and scheme ambiguities. Contact is made to earlier attempts to guess this effective potential from the conformal anomaly. We apply our results to the Improved Holographic QCD model calculating the glueball condensate., Comment: 46 pages, 5 figures

Published
2015
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23. Holographic RG flow and the quantum effective action

Author

Francesco Nitti, Wenliang Li, Elias Kiritsis, AstroParticule et Cosmologie (APC (UMR_7164)), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Observatoire de Paris, Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Université Paris Diderot - Paris 7 (UPD7)-Centre National de la Recherche Scientifique (CNRS), Observatoire de Paris, and Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Paris Diderot - Paris 7 (UPD7)-Centre National de la Recherche Scientifique (CNRS)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)

Subjects
High Energy Physics - Theory, Physics, [PHYS]Physics [physics], Scalar (mathematics), Holography, FOS: Physical sciences, General Physics and Astronomy, Ricci flow, Conserved quantity, law.invention, Formalism (philosophy of mathematics), High Energy Physics - Theory (hep-th), law, [PHYS.ASTR]Physics [physics]/Astrophysics [astro-ph], Effective action, Quantum, ComputingMilieux_MISCELLANEOUS, Mathematical physics
Abstract

The calculation of the full (renormalized) holographic action is undertaken in general Einstein-scalar theories. The appropriate formalism is developed and the renormalized effective action is calculated up to two derivatives in the metric and scalar operators. The holographic RG equations involve Ricci flow for the space-time metric as well as the standard $\beta$-function flow for scalar operators. Several examples are analyzed and the effective action is calculated. A set of conserved quantities of the holographic flow is found, whose interpretation is not yet understood., Comment: 85 pages, 6 figures. v2: three subsections and one appendix added with a more detailed discussion of local RG transformations, RG invariance of the renormalized action, trace identities and scheme dependence; discussion added about the distinction between RG-invariant and RG scale-dependent operators; details added in sections 6 and 7; typos corrected, references added

Published
2014
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24. The Chern-Simons diffusion rate in improved holographic QCD

Author

Umut Gürsoy, Francesco Nitti, Elias Kiritsis, Andy O'Bannon, Ioannis Iatrakis, Theoretical Physics, Sub String Theory Cosmology and ElemPart, Institute of Physics, Utrecht University [Utrecht], Crete Center for Theoretical Physics [Heraklion] (CCTP), University of Crete [Heraklion] (UOC), AstroParticule et Cosmologie (APC (UMR_7164)), Observatoire de Paris, Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Paris Diderot - Paris 7 (UPD7)-Centre National de la Recherche Scientifique (CNRS)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3), Department of Applied Mathematics and Theoretical Physics (DAMTP), University of Cambridge [UK] (CAM), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Observatoire de Paris, Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Université Paris Diderot - Paris 7 (UPD7)-Centre National de la Recherche Scientifique (CNRS), Crete Center for Theoretical Physics (CCTP), APC - THEORIE, Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Centre National de la Recherche Scientifique (CNRS)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Observatoire de Paris, PSL Research University (PSL)-PSL Research University (PSL)-Université Paris Diderot - Paris 7 (UPD7)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Centre National de la Recherche Scientifique (CNRS)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Observatoire de Paris, PSL Research University (PSL)-PSL Research University (PSL)-Université Paris Diderot - Paris 7 (UPD7)-Institut für theoretische Physik, Universität Hamburg (UHH)-Universität Hamburg (UHH), PSL Research University (PSL)-PSL Research University (PSL)-Université Paris Diderot - Paris 7 (UPD7), and Department of Applied Mathematics and Theoretical Physics / Centre for Mathematical Sciences (DAMTP/CMS)

Subjects
High Energy Physics - Theory, Nuclear and High Energy Physics, High Energy Physics::Lattice, Chern–Simons theory, FOS: Physical sciences, Field strength, 7. Clean energy, 01 natural sciences, Deconfinement, Momentum, High Energy Physics - Phenomenology (hep-ph), High Energy Physics - Lattice, 0103 physical sciences, 010306 general physics, Mathematical physics, Physics, Quantum chromodynamics, 010308 nuclear & particles physics, Glueball, [PHYS.HTHE]Physics [physics]/High Energy Physics - Theory [hep-th], Operator (physics), High Energy Physics - Lattice (hep-lat), High Energy Physics - Phenomenology, High Energy Physics - Theory (hep-th), Quark–gluon plasma, [PHYS.ASTR]Physics [physics]/Astrophysics [astro-ph]
Abstract

In (3+1)-dimensional SU(Nc) Yang-Mills (YM) theory, the Chern-Simons diffusion rate, Gamma_{CS}, is determined by the zero-momentum, zero-frequency limit of the retarded two-point function of the CP-odd operator tr[F ^ F], with F the YM field strength. The Chern-Simons diffusion rate is a crucial ingredient for many CP-odd phenomena, including the chiral magnetic effect in the quark-gluon plasma. We compute Gamma_{CS} in the high-temperature, deconfined phase of Improved Holographic QCD, a refined holographic model for large-Nc YM theory. Our result for Gamma_{CS}/(sT), where s is entropy density and T is temperature, varies slowly at high T and increases monotonically as T approaches the transition temperature from above. We also study the retarded two-point function of tr[F ^ F] with non-zero frequency and momentum. Our results suggest that the CP-odd phenomena that may potentially occur in heavy ion collisions could be controlled by an excitation with energy on the order of the lightest axial glueball mass., 31 pages, 13 eps files in 11 figures; v2 added one footnote and two references, version published in JHEP

Published
2013
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25. Scalar-tensor theories, trace anomalies, and the QCD frame

Author

Francesco Nitti, Federico Piazza, AstroParticule et Cosmologie (APC (UMR_7164)), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Observatoire de Paris, Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Université Paris Diderot - Paris 7 (UPD7)-Centre National de la Recherche Scientifique (CNRS), APC - THEORIE, Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Centre National de la Recherche Scientifique (CNRS)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Observatoire de Paris, PSL Research University (PSL)-PSL Research University (PSL)-Université Paris Diderot - Paris 7 (UPD7)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Centre National de la Recherche Scientifique (CNRS)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Observatoire de Paris, PSL Research University (PSL)-PSL Research University (PSL)-Université Paris Diderot - Paris 7 (UPD7)-Institut für theoretische Physik, Universität Hamburg (UHH)-Universität Hamburg (UHH), PSL Research University (PSL)-PSL Research University (PSL)-Université Paris Diderot - Paris 7 (UPD7), Observatoire de Paris, and Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Paris Diderot - Paris 7 (UPD7)-Centre National de la Recherche Scientifique (CNRS)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)

Subjects
High Energy Physics - Theory, Nuclear and High Energy Physics, Geodesic, FOS: Physical sciences, General Relativity and Quantum Cosmology (gr-qc), 01 natural sciences, General Relativity and Quantum Cosmology, Gravitation, Theoretical physics, High Energy Physics - Phenomenology (hep-ph), 0103 physical sciences, 010306 general physics, Quantum chromodynamics, Physics, [PHYS.HTHE]Physics [physics]/High Energy Physics - Theory [hep-th], 010308 nuclear & particles physics, Scalar theories of gravitation, Decoupling (cosmology), Renormalization group, Gluon, High Energy Physics - Phenomenology, Classical mechanics, High Energy Physics - Theory (hep-th), [PHYS.HPHE]Physics [physics]/High Energy Physics - Phenomenology [hep-ph], [PHYS.GRQC]Physics [physics]/General Relativity and Quantum Cosmology [gr-qc], [PHYS.ASTR]Physics [physics]/Astrophysics [astro-ph], Phenomenology (particle physics)
Abstract

We consider the quantum effects of matter fields in scalar-tensor theories and clarify the role of trace anomaly when switching between conformally related `frames'. We exploit the property that the couplings between the scalar and the gauge fields are not frame-invariant in order to define a `QCD-frame', where the scalar is not coupled to the gluons. We show that this frame is a natural generalization of the `Jordan frame' in the case of non-metric theories and that it is particularly convenient for gravitational phenomenology: test bodies have trajectories that are as close as possible to geodesics with respect to such a metric and equivalence principle violations are directly proportional to the scalar coupling parameters written in this frame. We show how RG flow and decoupling work in metric and non-metric theories. RG-running commutes with the operation of switching between frames at different scales. When only matter loops are considered, our analysis confirms that metricity is stable under radiative corrections and shows that approximate metricity is natural in a technical sense., Comment: 10 pages. Minor changes to the main text, appendix added. To appear on PRD

Published
2012
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26. Dressed spectral densities for heavy quark diffusion in holographic plasmas

Author

Liuba Mazzanti, Elias Kiritsis, Francesco Nitti, AstroParticule et Cosmologie (APC (UMR_7164)), Observatoire de Paris, Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Paris Diderot - Paris 7 (UPD7)-Centre National de la Recherche Scientifique (CNRS)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Observatoire de Paris, Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Université Paris Diderot - Paris 7 (UPD7)-Centre National de la Recherche Scientifique (CNRS), APC - THEORIE, Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Centre National de la Recherche Scientifique (CNRS)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Observatoire de Paris, PSL Research University (PSL)-PSL Research University (PSL)-Université Paris Diderot - Paris 7 (UPD7)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Centre National de la Recherche Scientifique (CNRS)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Observatoire de Paris, PSL Research University (PSL)-PSL Research University (PSL)-Université Paris Diderot - Paris 7 (UPD7)-Institut für theoretische Physik, and Universität Hamburg (UHH)-Universität Hamburg (UHH)

Subjects
[PHYS]Physics [physics], Quark, Physics, High Energy Physics - Theory, Nuclear and High Energy Physics, [PHYS.HTHE]Physics [physics]/High Energy Physics - Theory [hep-th], 010308 nuclear & particles physics, FOS: Physical sciences, Duality (optimization), Context (language use), Conformal map, Gauge (firearms), 01 natural sciences, String (physics), High Energy Physics - Phenomenology, High Energy Physics - Phenomenology (hep-ph), High Energy Physics - Theory (hep-th), Diffusion process, [PHYS.HPHE]Physics [physics]/High Energy Physics - Phenomenology [hep-ph], Quantum electrodynamics, Dispersion relation, 0103 physical sciences, [PHYS.ASTR]Physics [physics]/Astrophysics [astro-ph], 010306 general physics
Abstract

We analyze the large frequency behavior of the spectral densities that govern the generalized Langevin diffusion process for a heavy quark in the context of the gauge/gravity duality. The bare Langevin correlators obtained from the trailing string solution have a singular short-distance behavior. We argue that the proper dressed spectral functions are obtained by subtracting the zero-temperature correlators. The dressed spectral functions have a sufficiently fast fall-off at large frequency so that the Langevin process is well defined and the dispersion relations are satisfied. We identify the cases in which the subtraction does not modify the associated low-frequency transport coefficients. These include conformal theories and the non-conformal, non-confining models. We provide several analytic and numerical examples in conformal and non-conformal holographic backgrounds., 51 pages, 2 figures

Published
2011
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27. Improved Holographic QCD

Author

Francesco Nitti, Liuba Mazzanti, Umut Gürsoy, Elias Kiritsis, Georgios Michalogiorgakis, APC - THEORIE, AstroParticule et Cosmologie (APC (UMR_7164)), Observatoire de Paris, Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Paris Diderot - Paris 7 (UPD7)-Centre National de la Recherche Scientifique (CNRS)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Observatoire de Paris, Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Paris Diderot - Paris 7 (UPD7)-Centre National de la Recherche Scientifique (CNRS)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Institut für theoretische Physik, Universität Hamburg (UHH)-Universität Hamburg (UHH), Eleftherios Papantonopoulos, Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Observatoire de Paris, Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Université Paris Diderot - Paris 7 (UPD7)-Centre National de la Recherche Scientifique (CNRS)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Observatoire de Paris, Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Université Paris Diderot - Paris 7 (UPD7)-Centre National de la Recherche Scientifique (CNRS)-Institut für theoretische Physik, Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Centre National de la Recherche Scientifique (CNRS)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Observatoire de Paris, PSL Research University (PSL)-PSL Research University (PSL)-Université Paris Diderot - Paris 7 (UPD7)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Centre National de la Recherche Scientifique (CNRS)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Observatoire de Paris, and PSL Research University (PSL)-PSL Research University (PSL)-Université Paris Diderot - Paris 7 (UPD7)-Institut für theoretische Physik

Subjects
Quantum chromodynamics, Physics, 010308 nuclear & particles physics, Glueball, [PHYS.HLAT]Physics [physics]/High Energy Physics - Lattice [hep-lat], [PHYS.HTHE]Physics [physics]/High Energy Physics - Theory [hep-th], High Energy Physics::Lattice, Volume viscosity, Plasma, 01 natural sciences, Spectral line, Drag, Quantum electrodynamics, Lattice (order), [PHYS.HPHE]Physics [physics]/High Energy Physics - Phenomenology [hep-ph], 0103 physical sciences, 010306 general physics, Jet quenching
Abstract

LatEX, 65 pages, 28 figures, 9 Tables. Based on lectures given at several Schools. To appear in the proceedinds of the 5th Aegean School (Milos, Greece); International audience; We provide a review to holographic models based on Einstein-dilaton gravity with a potential in 5 dimensions. Such theories, for a judicious choice of potential are very close to the physics of large-N YM theory both at zero and finite temperature. The zero temperature glueball spectra as well as their finite temperature thermodynamic functions compare well with lattice data. The model can be used to calculate transport coefficients, like bulk viscosity, the drag force and jet quenching parameters, relevant for the physics of the Quark-Gluon Plasma.

Published
2011
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28. Langevin Dynamics of Heavy Quarks in 5D Holographic QCD models

Author

Francesco Nitti, AstroParticule et Cosmologie (APC (UMR_7164)), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Observatoire de Paris, and Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Université Paris Diderot - Paris 7 (UPD7)-Centre National de la Recherche Scientifique (CNRS)

Subjects
Physics, Quantum chromodynamics, Quark, Particle physics, High Energy Physics::Lattice, High Energy Physics::Phenomenology, Langevin equation, Strange matter, Quantum electrodynamics, Brownian dynamics, High Energy Physics::Experiment, Brillouin and Langevin functions, [PHYS.ASTR]Physics [physics]/Astrophysics [astro-ph], Nuclear Experiment, Langevin dynamics, Jet quenching
Abstract

International audience; I discuss the holographic approach to the Langevin equation describing the motion of a heavy quark propagating through the deconfined Quark-Gluon Plasma (QGP). The Langevin diffusion coefficients are directly related to the jet quenching parameter, which enters in the reconstruction of RHIC events involving heavy probes. After a brief review of the Langevin equation, I discuss the calculation of the Langevin coefficients in 5-dimensional holographic duals. Finally, I discuss the results for the jet quenching parameter in a phenomenological holographic QCD model.

Published
2011
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29. Thermal Transport and Drag Force in Improved Holographic QCD

Author

Umut Gürsoy, Francesco Nitti, Elias Kiritsis, Georgios Michalogiorgakis, Department of Physics [Heraklion], University of Crete [Heraklion] (UOC), AstroParticule et Cosmologie (APC (UMR_7164)), Observatoire de Paris, Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Paris Diderot - Paris 7 (UPD7)-Centre National de la Recherche Scientifique (CNRS)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3), Centre de Physique Théorique [Palaiseau] (CPHT), Centre National de la Recherche Scientifique (CNRS)-École polytechnique (X), APC - THEORIE, Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Paris Diderot - Paris 7 (UPD7)-Centre National de la Recherche Scientifique (CNRS)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Observatoire de Paris, Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Paris Diderot - Paris 7 (UPD7)-Centre National de la Recherche Scientifique (CNRS)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Institut für theoretische Physik, Universität Hamburg (UHH)-Universität Hamburg (UHH), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Observatoire de Paris, Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Université Paris Diderot - Paris 7 (UPD7)-Centre National de la Recherche Scientifique (CNRS), École polytechnique (X)-Centre National de la Recherche Scientifique (CNRS), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Université Paris Diderot - Paris 7 (UPD7)-Centre National de la Recherche Scientifique (CNRS)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Observatoire de Paris, Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Université Paris Diderot - Paris 7 (UPD7)-Centre National de la Recherche Scientifique (CNRS)-Institut für theoretische Physik, Physics Department, Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Centre National de la Recherche Scientifique (CNRS)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Observatoire de Paris, PSL Research University (PSL)-PSL Research University (PSL)-Université Paris Diderot - Paris 7 (UPD7), PSL Research University (PSL)-PSL Research University (PSL)-Université Paris Diderot - Paris 7 (UPD7)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Centre National de la Recherche Scientifique (CNRS)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Observatoire de Paris, PSL Research University (PSL)-PSL Research University (PSL)-Université Paris Diderot - Paris 7 (UPD7)-Institut für theoretische Physik, Instituut Theoretische Fysica, Theoretical Physics, and Sub String Theory Cosmology and ElemPart

Subjects
High Energy Physics - Theory, Nuclear and High Energy Physics, Phase transition, Particle physics, Wilson loop, Nuclear Theory, [PHYS.NUCL]Physics [physics]/Nuclear Theory [nucl-th], High Energy Physics::Lattice, FOS: Physical sciences, 01 natural sciences, Asymptotic freedom, Nuclear Theory (nucl-th), Physics::Fluid Dynamics, High Energy Physics - Phenomenology (hep-ph), 0103 physical sciences, Diffusion (business), 010306 general physics, Jet quenching, Particle Physics - Phenomenology, Quantum chromodynamics, Physics, 010308 nuclear & particles physics, [PHYS.HTHE]Physics [physics]/High Energy Physics - Theory [hep-th], Volume viscosity, Mechanics, High Energy Physics - Phenomenology, High Energy Physics - Theory (hep-th), Drag, [PHYS.HPHE]Physics [physics]/High Energy Physics - Phenomenology [hep-ph]
Abstract

We calculate the bulk viscosity, drag force and jet quenching parameter in Improved Holographic QCD. We find that the bulk viscosity rises near the phase transition but does not exceed the shear viscosity. The drag force shows the effects of asymptotic freedom both as a function of velocity and temperature. It indicates diffusion times of heavy quarks in rough agreement with data. The jet quenching parameter values computed via the light-like Wilson loop are in the lower range suggested by data., Comment: Latex, 61 pages, 18 eps figures. Published version: bulk viscosity section expanded, discussion improved, 2 appendices added; v3: minor mistakes corrected; v4: mistake in eq. (4.21) corrected.

Published
2009
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30. Holography and Thermodynamics of 5D Dilaton-gravity

Author

Elias Kiritsis, Umut Gürsoy, Francesco Nitti, Liuba Mazzanti, Physics Department, University of Crete [Heraklion] (UOC), AstroParticule et Cosmologie (APC (UMR_7164)), Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Centre National de la Recherche Scientifique (CNRS)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Observatoire de Paris, PSL Research University (PSL)-PSL Research University (PSL)-Université Paris Diderot - Paris 7 (UPD7), Centre de Physique Théorique [Palaiseau] (CPHT), École polytechnique (X)-Centre National de la Recherche Scientifique (CNRS), APC - THEORIE, PSL Research University (PSL)-PSL Research University (PSL)-Université Paris Diderot - Paris 7 (UPD7)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Centre National de la Recherche Scientifique (CNRS)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Observatoire de Paris, PSL Research University (PSL)-PSL Research University (PSL)-Université Paris Diderot - Paris 7 (UPD7)-Institut für theoretische Physik, Universität Hamburg (UHH)-Universität Hamburg (UHH), Department of Physics [Heraklion], Observatoire de Paris, Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Paris Diderot - Paris 7 (UPD7)-Centre National de la Recherche Scientifique (CNRS)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3), Centre National de la Recherche Scientifique (CNRS)-École polytechnique (X), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Paris Diderot - Paris 7 (UPD7)-Centre National de la Recherche Scientifique (CNRS)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Observatoire de Paris, Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Paris Diderot - Paris 7 (UPD7)-Centre National de la Recherche Scientifique (CNRS)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Institut für theoretische Physik, Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Observatoire de Paris, Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Université Paris Diderot - Paris 7 (UPD7)-Centre National de la Recherche Scientifique (CNRS), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Université Paris Diderot - Paris 7 (UPD7)-Centre National de la Recherche Scientifique (CNRS)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Observatoire de Paris, Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Université Paris Diderot - Paris 7 (UPD7)-Centre National de la Recherche Scientifique (CNRS)-Institut für theoretische Physik, Instituut Theoretische Fysica, Theoretical Physics, and Sub String Theory Cosmology and ElemPart

Subjects
High Energy Physics - Theory, Nuclear and High Energy Physics, gr-qc, Critical phenomena, High Energy Physics::Lattice, FOS: Physical sciences, General Relativity and Quantum Cosmology (gr-qc), 01 natural sciences, Deconfinement, Asymptotic freedom, General Relativity and Quantum Cosmology, High Energy Physics::Theory, High Energy Physics - Phenomenology (hep-ph), 0103 physical sciences, 010306 general physics, Topological quantum number, Mathematical physics, Physics, 010308 nuclear & particles physics, [PHYS.HTHE]Physics [physics]/High Energy Physics - Theory [hep-th], hep-th, hep-ph, Gluon condensate, 3. Good health, Gluon, High Energy Physics - Phenomenology, AdS/CFT correspondence, High Energy Physics - Theory (hep-th), [PHYS.HPHE]Physics [physics]/High Energy Physics - Phenomenology [hep-ph], [PHYS.GRQC]Physics [physics]/General Relativity and Quantum Cosmology [gr-qc], Dilaton
Abstract

The asymptotically-logarithmically-AdS black-hole solutions of 5D dilaton gravity with a monotonic dilaton potential are analyzed in detail. Such theories are holographically very close to pure Yang-Mills theory in four dimensions. The existence and uniqueness of black-hole solutions is shown. It is also shown that a Hawking-Page transition exists at finite temperature if and only if the potential corresponds to a confining theory. The physics of the transition matches in detail with that of deconfinement of the Yang-Mills theory. The high-temperature phase asymptotes to a free gluon gas at high temperature matching the expected behavior from asymptotic freedom. The thermal gluon condensate is calculated and shown to be crucial for the existence of a non-trivial deconfining transition. The condensate of the topological charge is shown to vanish in the deconfined phase., Comment: LaTeX, 61 pages (main body) + 58 pages (appendix), 25 eps figures. Revised version, published in JHEP. Two equations added in Section 7.4; typos corrected; references added

Published
2009
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31. Improved Holographic Yang-Mills at Finite Temperature: Comparison with Data

Author

Elias Kiritsis, Liuba Mazzanti, Francesco Nitti, Umut Gürsoy, Centre de Physique Théorique [Palaiseau] (CPHT), École polytechnique (X)-Centre National de la Recherche Scientifique (CNRS), Laboratoire de Physique Théorique de l'ENS (LPTENS), Fédération de recherche du Département de physique de l'Ecole Normale Supérieure - ENS Paris (FRDPENS), Centre National de la Recherche Scientifique (CNRS)-École normale supérieure - Paris (ENS Paris)-Centre National de la Recherche Scientifique (CNRS)-École normale supérieure - Paris (ENS Paris)-Université Pierre et Marie Curie - Paris 6 (UPMC)-Centre National de la Recherche Scientifique (CNRS), Physics Department, University of Crete [Heraklion] (UOC), AstroParticule et Cosmologie (APC (UMR_7164)), Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Centre National de la Recherche Scientifique (CNRS)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Observatoire de Paris, PSL Research University (PSL)-PSL Research University (PSL)-Université Paris Diderot - Paris 7 (UPD7), APC - THEORIE, PSL Research University (PSL)-PSL Research University (PSL)-Université Paris Diderot - Paris 7 (UPD7)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Centre National de la Recherche Scientifique (CNRS)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Observatoire de Paris, PSL Research University (PSL)-PSL Research University (PSL)-Université Paris Diderot - Paris 7 (UPD7)-Institut für theoretische Physik, Universität Hamburg (UHH)-Universität Hamburg (UHH), Centre National de la Recherche Scientifique (CNRS)-École polytechnique (X), Université Pierre et Marie Curie - Paris 6 (UPMC)-Fédération de recherche du Département de physique de l'Ecole Normale Supérieure - ENS Paris (FRDPENS), École normale supérieure - Paris (ENS Paris), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Centre National de la Recherche Scientifique (CNRS)-École normale supérieure - Paris (ENS Paris), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Centre National de la Recherche Scientifique (CNRS)-Centre National de la Recherche Scientifique (CNRS), Department of Physics [Heraklion], Observatoire de Paris, Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Paris Diderot - Paris 7 (UPD7)-Centre National de la Recherche Scientifique (CNRS)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Paris Diderot - Paris 7 (UPD7)-Centre National de la Recherche Scientifique (CNRS)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Observatoire de Paris, Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Paris Diderot - Paris 7 (UPD7)-Centre National de la Recherche Scientifique (CNRS)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Institut für theoretische Physik, Laboratoire de Physique Théorique de l'ENS [École Normale Supérieure] (LPTENS), École normale supérieure - Paris (ENS-PSL), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Centre National de la Recherche Scientifique (CNRS)-École normale supérieure - Paris (ENS-PSL), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Centre National de la Recherche Scientifique (CNRS)-Université Pierre et Marie Curie - Paris 6 (UPMC)-Centre National de la Recherche Scientifique (CNRS), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Observatoire de Paris, Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Université Paris Diderot - Paris 7 (UPD7)-Centre National de la Recherche Scientifique (CNRS), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Université Paris Diderot - Paris 7 (UPD7)-Centre National de la Recherche Scientifique (CNRS)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Observatoire de Paris, Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Université Paris Diderot - Paris 7 (UPD7)-Centre National de la Recherche Scientifique (CNRS)-Institut für theoretische Physik, Instituut Theoretische Fysica, Theoretical Physics, and Sub String Theory Cosmology and ElemPart

Subjects
High Energy Physics - Theory, Nuclear and High Energy Physics, High Energy Physics::Lattice, Holography, FOS: Physical sciences, Yang–Mills existence and mass gap, 01 natural sciences, law.invention, High Energy Physics - Phenomenology (hep-ph), High Energy Physics - Lattice, law, 0103 physical sciences, Gauge theory, 010306 general physics, Quantum chromodynamics, Physics, Rest (physics), [PHYS.HLAT]Physics [physics]/High Energy Physics - Lattice [hep-lat], [PHYS.HTHE]Physics [physics]/High Energy Physics - Theory [hep-th], 010308 nuclear & particles physics, Glueball, High Energy Physics - Lattice (hep-lat), Observable, High Energy Physics - Phenomenology, High Energy Physics - Theory (hep-th), [PHYS.HPHE]Physics [physics]/High Energy Physics - Phenomenology [hep-ph], Quantum electrodynamics, Tower
Abstract

The semi-phenomenological improved holographic model for QCD is confronted with data of the pure glue, large-Nc gauge theory. After fitting two phenomenological parameters in the potential, the model can reproduce in detail all thermodynamic functions at finite temperature. It also reproduces in detail all known spin-0 and spin-2 glueball observables at zero temperature and predicts the rest of the 0++ and 2++ towers. A similar two parameter fit in the CP-odd sector postdicts the correct second 0+- glueball mass, and predicts the rest of the 0+- tower., 36 pages, 10 figures; references added, minor typos corrected; v3: corrected numerical mistake in section 5.4.

Published
2009
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32. Exploring improved holographic theories for QCD: part I

Author

Francesco Nitti, Umut Gürsoy, Elias Kiritsis, Centre de Physique Théorique [Palaiseau] (CPHT), Centre National de la Recherche Scientifique (CNRS)-École polytechnique (X), Laboratoire de Physique Théorique de l'ENS (LPTENS), Université Pierre et Marie Curie - Paris 6 (UPMC)-Fédération de recherche du Département de physique de l'Ecole Normale Supérieure - ENS Paris (FRDPENS), École normale supérieure - Paris (ENS Paris), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Centre National de la Recherche Scientifique (CNRS)-École normale supérieure - Paris (ENS Paris), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Centre National de la Recherche Scientifique (CNRS)-Centre National de la Recherche Scientifique (CNRS), APC - THEORIE, AstroParticule et Cosmologie (APC (UMR_7164)), Observatoire de Paris, Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Paris Diderot - Paris 7 (UPD7)-Centre National de la Recherche Scientifique (CNRS)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Observatoire de Paris, Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Paris Diderot - Paris 7 (UPD7)-Centre National de la Recherche Scientifique (CNRS)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Institut für theoretische Physik, Universität Hamburg (UHH)-Universität Hamburg (UHH), École polytechnique (X)-Centre National de la Recherche Scientifique (CNRS), Laboratoire de Physique Théorique de l'ENS [École Normale Supérieure] (LPTENS), Fédération de recherche du Département de physique de l'Ecole Normale Supérieure - ENS Paris (FRDPENS), École normale supérieure - Paris (ENS-PSL), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Centre National de la Recherche Scientifique (CNRS)-École normale supérieure - Paris (ENS-PSL), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Centre National de la Recherche Scientifique (CNRS)-Université Pierre et Marie Curie - Paris 6 (UPMC)-Centre National de la Recherche Scientifique (CNRS), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Observatoire de Paris, Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Université Paris Diderot - Paris 7 (UPD7)-Centre National de la Recherche Scientifique (CNRS)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Observatoire de Paris, Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Université Paris Diderot - Paris 7 (UPD7)-Centre National de la Recherche Scientifique (CNRS)-Institut für theoretische Physik, Centre National de la Recherche Scientifique (CNRS)-École normale supérieure - Paris (ENS Paris)-Centre National de la Recherche Scientifique (CNRS)-École normale supérieure - Paris (ENS Paris)-Université Pierre et Marie Curie - Paris 6 (UPMC)-Centre National de la Recherche Scientifique (CNRS), Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Centre National de la Recherche Scientifique (CNRS)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Observatoire de Paris, PSL Research University (PSL)-PSL Research University (PSL)-Université Paris Diderot - Paris 7 (UPD7)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Centre National de la Recherche Scientifique (CNRS)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Observatoire de Paris, and PSL Research University (PSL)-PSL Research University (PSL)-Université Paris Diderot - Paris 7 (UPD7)-Institut für theoretische Physik

Subjects
High Energy Physics - Theory, Nuclear and High Energy Physics, High Energy Physics::Lattice, Vacuum state, FOS: Physical sciences, String theory, 01 natural sciences, Asymptotic freedom, Theoretical physics, High Energy Physics - Phenomenology (hep-ph), Singularity, High Energy Physics - Lattice, 0103 physical sciences, 010306 general physics, Quantum chromodynamics, Physics, 010308 nuclear & particles physics, Glueball, [PHYS.HLAT]Physics [physics]/High Energy Physics - Lattice [hep-lat], [PHYS.HTHE]Physics [physics]/High Energy Physics - Theory [hep-th], High Energy Physics - Lattice (hep-lat), High Energy Physics::Phenomenology, Lattice QCD, High Energy Physics - Phenomenology, High Energy Physics - Theory (hep-th), [PHYS.HPHE]Physics [physics]/High Energy Physics - Phenomenology [hep-ph], Dilaton, High Energy Physics::Experiment
Abstract

Various holographic approaches to QCD in five dimensions are explored using input both from the putative non-critical string theory as well as QCD. It is argued that a gravity theory in five dimensions coupled to a dilaton and an axion may capture the important qualitative features of pure QCD. A part of the higher alpha' corrections are resummed into a dilaton potential. The potential is shown to be in one-to-one correspondence with the exact beta-function of QCD, and its knowledge determines the full structure of the vacuum solution. The geometry near the UV boundary is that of AdS_5 with logarithmic corrections reflecting the asymptotic freedom of QCD. We find that all relevant confining backgrounds have an IR singularity of the "good" kind that allows unambiguous spectrum computations. Near the singularity the 't Hooft coupling is driven to infinity. Asymptotically linear glueball masses can also be achieved. The classification of all confining asymptotics, the associated glueball spectra and meson dynamics are addressed in a companion paper, ArXiv:0707.1349, 37+23 pages, 11 figures. (v3) Some clarifications and typo corrections. Journal version

Published
2008
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33. Holography and Emergent 4D Gravity

Author

Francesco Nitti and Nitti, Francesco

Subjects
Physics, High Energy Physics - Theory, Nuclear and High Energy Physics, Holography, Graviton, General Physics and Astronomy, FOS: Physical sciences, Astronomy and Astrophysics, law.invention, [PHYS.HPHE] Physics [physics]/High Energy Physics - Phenomenology [hep-ph], Theoretical physics, High Energy Physics - Phenomenology, High Energy Physics - Phenomenology (hep-ph), High Energy Physics - Theory (hep-th), law, [PHYS.HTHE] Physics [physics]/High Energy Physics - Theory [hep-th], Phenomenology (particle physics)
Abstract

I review recent work toward constructing, via five-dimensional holographic duals, four-dimensional theories in which spin-2 states (gravitons) are emergent. The basic idea is to extend to gravity model-building the applications of holographic duality to phenomenology construction., 14 pages, 1 figure. Invited review for Modern Physics Letters A. Journal version; minor typos corrected

Published
2008

34. Metastable Vacua in Brane Worlds

Author

J. Mourad, Emilian Dudas, Francesco Nitti, Laboratoire de Physique Théorique d'Orsay [Orsay] (LPT), Université Paris-Sud - Paris 11 (UP11)-Centre National de la Recherche Scientifique (CNRS), Centre de Physique Théorique [Palaiseau] (CPHT), École polytechnique (X)-Centre National de la Recherche Scientifique (CNRS), APC - THEORIE, AstroParticule et Cosmologie (APC (UMR_7164)), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Observatoire de Paris, Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Université Paris Diderot - Paris 7 (UPD7)-Centre National de la Recherche Scientifique (CNRS)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Observatoire de Paris, Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Université Paris Diderot - Paris 7 (UPD7)-Centre National de la Recherche Scientifique (CNRS)-Institut für theoretische Physik, Universität Hamburg (UHH)-Universität Hamburg (UHH), Centre National de la Recherche Scientifique (CNRS)-Université Paris-Sud - Paris 11 (UP11), Centre National de la Recherche Scientifique (CNRS)-École polytechnique (X), Observatoire de Paris, Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Paris Diderot - Paris 7 (UPD7)-Centre National de la Recherche Scientifique (CNRS)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Observatoire de Paris, Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Paris Diderot - Paris 7 (UPD7)-Centre National de la Recherche Scientifique (CNRS)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Institut für theoretische Physik, Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Centre National de la Recherche Scientifique (CNRS)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Observatoire de Paris, PSL Research University (PSL)-PSL Research University (PSL)-Université Paris Diderot - Paris 7 (UPD7)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Centre National de la Recherche Scientifique (CNRS)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Observatoire de Paris, and PSL Research University (PSL)-PSL Research University (PSL)-Université Paris Diderot - Paris 7 (UPD7)-Institut für theoretische Physik

Subjects
High Energy Physics - Theory, Physics, Nuclear and High Energy Physics, 010308 nuclear & particles physics, [PHYS.HTHE]Physics [physics]/High Energy Physics - Theory [hep-th], FOS: Physical sciences, 01 natural sciences, High Energy Physics - Phenomenology, Theoretical physics, General Relativity and Quantum Cosmology, High Energy Physics::Theory, High Energy Physics - Phenomenology (hep-ph), High Energy Physics - Theory (hep-th), Metastability, 0103 physical sciences, Brane, 010306 general physics, Degeneracy (mathematics), Scalar field, False vacuum
Abstract

We analyze vacuum decay in brane world setups, where a free scalar field in five dimensions has a localized potential admitting metastable vacua. We study in particular the bounce solution and its properties in flat and warped spaces. In the latter case, placing into a deeply warped region the term in the potential that lifts the vacuum degeneracy, can increase indefinitely the lifetime of the false vacuum. We discuss the application to metastable vacua in supersymmetric brane-world constructions., Comment: LaTeX, 24 pages

Published
2007
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35. Naturalness in Cosmological Initial Conditions

Author

Francesco Nitti, Jan-Willem Rombouts, and Massimo Porrati

Subjects
Physics, Inflation (cosmology), High Energy Physics - Theory, Nuclear and High Energy Physics, Quantum field theory in curved spacetime, 010308 nuclear & particles physics, Astrophysics (astro-ph), Boundary (topology), FOS: Physical sciences, General Relativity and Quantum Cosmology (gr-qc), Astrophysics, 01 natural sciences, General Relativity and Quantum Cosmology, Theoretical physics, Classical mechanics, Naturalness, High Energy Physics - Theory (hep-th), 0103 physical sciences, Effective field theory, Brane cosmology, Boundary value problem, 010306 general physics, Effective action
Abstract

We propose a novel approach to the problem of constraining cosmological initial conditions. Within the framework of effective field theory, we classify initial conditions in terms of boundary terms added to the effective action describing the cosmological evolution below Planckian energies. These boundary terms can be thought of as spacelike branes which may support extra instantaneous degrees of freedom and extra operators. Interactions and renormalization of these boundary terms allow us to apply to the boundary terms the field-theoretical requirement of naturalness, i.e. stability under radiative corrections. We apply this requirement to slow-roll inflation with non-adiabatic initial conditions, and to cyclic cosmology. This allows us to define in a precise sense when some of these models are fine-tuned. We also describe how to parametrize in a model-independent way non-Gaussian initial conditions; we show that in some cases they are both potentially observable and pass our naturalness requirement., 35 pages, 8 figures

Published
2005

36. Power of brane-induced gravity

Author

Marko Kolanović, Francesco Nitti, Gregory Gabadadze, and Gia Dvali

Subjects
Physics, Nuclear and High Energy Physics, 010308 nuclear & particles physics, Graviton, Planck mass, 01 natural sciences, Universal extra dimension, General Relativity and Quantum Cosmology, Extra dimensions, Theoretical physics, Quantum mechanics, 0103 physical sciences, Brane cosmology, Large extra dimension, Brane, 010306 general physics, Induced gravity
Abstract

We study the role of the brane-induced graviton kinetic term in theories with large extra dimensions. In five dimensions, we construct a model with a TeV-scale fundamental Planck mass and a flat extra dimension the size of which can be astronomically large. Four-dimensional (4D) gravity on the brane is mediated by a massless zero mode, whereas the couplings of the heavy Kaluza-Klein modes to ordinary matter are suppressed. The model can manifest itself through the predicted deviations from Einstein theory in long-distance precision measurements of the planetary orbits. The bulk states can be a rather exotic form of dark matter, which at subsolar distances interact via strong 5D gravitational force. We show that the induced term changes dramatically the phenomenology of submillimeter extra dimensions. For instance, high-energy constraints from star cooling or cosmology can be substantially relaxed.

Published
2001
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37. Scales of Gravity

Author

Francesco Nitti, Gregory Gabadadze, Gia Dvali, and Marko Kolanović

Subjects
Physics, High Energy Physics - Theory, Nuclear and High Energy Physics, 010308 nuclear & particles physics, Hořava–Lifshitz gravity, FOS: Physical sciences, Hierarchy problem, Euclidean quantum gravity, 01 natural sciences, High Energy Physics - Phenomenology, General Relativity and Quantum Cosmology, High Energy Physics::Theory, High Energy Physics - Phenomenology (hep-ph), High Energy Physics - Theory (hep-th), Quantum mechanics, 0103 physical sciences, Gravity well, Quantum gravity, Large extra dimension, Semiclassical gravity, f(R) gravity, 010306 general physics
Abstract

We propose a framework in which the quantum gravity scale can be as low as $10^{-3}$ eV. The key assumption is that the Standard Model ultraviolet cutoff is much higher than the quantum gravity scale. This ensures that we observe conventional weak gravity. We construct an explicit brane-world model in which the brane-localized Standard Model is coupled to strong 5D gravity of infinite-volume flat extra space. Due to the high ultraviolet scale, the Standard Model fields generate a large graviton kinetic term on the brane. This kinetic term ``shields'' the Standard Model from the strong bulk gravity. As a result, an observer on the brane sees weak 4D gravity up to astronomically large distances beyond which gravity becomes five-dimensional. Modeling quantum gravity above its scale by the closed string spectrum we show that the shielding phenomenon protects the Standard Model from an apparent phenomenological catastrophe due to the exponentially large number of light string states. The collider experiments, astrophysics, cosmology and gravity measurements {\it independently} point to the same lower bound on the quantum gravity scale, $10^{-3}$ eV. For this value the model has experimental signatures both for colliders and for sub-millimeter gravity measurements. Black holes reveal certain interesting properties in this framework., Comment: 51 pages; 7 ps figures; v2 minor improvements

Published
2001
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42. Axion RG flows and the holographic dynamics of instanton densities.

Author

Yuta Hamada, Elias Kiritsis, Francesco Nitti, and Lukas T Witkowski

Subjects
INSTANTONS, AXIONS, DENSITY, EXERCISE
Abstract

Axionic holographic RG flow solutions are studied in the context of general Einstein-axion-dilaton theories. A non-trivial axion profile is dual to the (non-perturbative) running of the -term for the corresponding instanton density operator. It is shown that a non-trivial axion solution is incompatible with a non-trivial (holographic) IR conformal fixed point. Imposing a suitable axion regularity condition allows to select the IR geometry in a unique way. The solutions are found analytically in the asymptotic UV and IR regimes, and it is shown that in those regimes the axion backreaction is always negligible. The axion backreaction may become important in the intermediate region of the bulk. To make contact with the axion probe limit solutions, a systematic expansion of the solution is developed. Several concrete examples are worked out numerically. It is shown that the regularity condition always implies a finite allowed range for the axion source parameter in the UV. This translates into the existence of a finite (but large) number of saddle-points in the large Nc limit. This ties in well with axion-swampland conjectures. [ABSTRACT FROM AUTHOR]

Published
2019
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43. Polarized solutions and Fermi surfaces in holographic Bose-Fermi systems

Author

Francesco Nitti, Giuseppe Policastro, Thomas Vanel, AstroParticule et Cosmologie (APC (UMR_7164)), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Observatoire de Paris, Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Université Paris Diderot - Paris 7 (UPD7)-Centre National de la Recherche Scientifique (CNRS), Laboratoire de Physique Théorique de l'ENS [École Normale Supérieure] (LPTENS), Fédération de recherche du Département de physique de l'Ecole Normale Supérieure - ENS Paris (FRDPENS), École normale supérieure - Paris (ENS-PSL), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Centre National de la Recherche Scientifique (CNRS)-École normale supérieure - Paris (ENS-PSL), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Centre National de la Recherche Scientifique (CNRS)-Université Pierre et Marie Curie - Paris 6 (UPMC)-Centre National de la Recherche Scientifique (CNRS), Laboratoire de Physique Théorique et Hautes Energies (LPTHE), Université Pierre et Marie Curie - Paris 6 (UPMC)-Centre National de la Recherche Scientifique (CNRS), Observatoire de Paris, Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Paris Diderot - Paris 7 (UPD7)-Centre National de la Recherche Scientifique (CNRS)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3), Laboratoire de Physique Théorique de l'ENS (LPTENS), Université Pierre et Marie Curie - Paris 6 (UPMC)-Fédération de recherche du Département de physique de l'Ecole Normale Supérieure - ENS Paris (FRDPENS), École normale supérieure - Paris (ENS Paris), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Centre National de la Recherche Scientifique (CNRS)-École normale supérieure - Paris (ENS Paris), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Centre National de la Recherche Scientifique (CNRS)-Centre National de la Recherche Scientifique (CNRS), Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Centre National de la Recherche Scientifique (CNRS)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Observatoire de Paris, PSL Research University (PSL)-PSL Research University (PSL)-Université Paris Diderot - Paris 7 (UPD7), and Centre National de la Recherche Scientifique (CNRS)-École normale supérieure - Paris (ENS Paris)-Centre National de la Recherche Scientifique (CNRS)-École normale supérieure - Paris (ENS Paris)-Université Pierre et Marie Curie - Paris 6 (UPMC)-Centre National de la Recherche Scientifique (CNRS)

Subjects
Physics, High Energy Physics - Theory, Condensed Matter::Quantum Gases, Antiparticle, Nuclear and High Energy Physics, Strongly Correlated Electrons (cond-mat.str-el), 010308 nuclear & particles physics, [PHYS.HTHE]Physics [physics]/High Energy Physics - Theory [hep-th], Operator (physics), Scalar (mathematics), Degrees of freedom (physics and chemistry), FOS: Physical sciences, Fermion, 01 natural sciences, Electric charge, Condensed Matter - Strongly Correlated Electrons, General Relativity and Quantum Cosmology, High Energy Physics - Theory (hep-th), Quantum mechanics, 0103 physical sciences, 010306 general physics, Ground state, [PHYS.ASTR]Physics [physics]/Astrophysics [astro-ph], Scalar field
Abstract

We use holography to study the ground state of a system with interacting bosonic and fermionic degrees of freedom at finite density. The gravitational model consists of Einstein-Maxwell gravity coupled to a perfect fluid of charged fermions and to a charged scalar field which interact through a current-current interaction. When the scalar field is non-trivial, in addition to compact electron stars, the screening of the fermion electric charge by the scalar condensate allows the formation of solutions where the fermion fluid is made of antiparticles, as well as solutions with coexisting, separated regions of particle-like and antiparticle-like fermion fluids. We show that, when the latter solutions exist, they are thermodynamically favored. By computing the two-point Green function of the boundary fermionic operator we show that, in addition to the charged scalar condensate, the dual field theory state exhibits electron-like and/or hole-like Fermi surfaces. Compared to fluid-only solutions, the presence of the scalar condensate destroys the Fermi surfaces with lowest Fermi momenta. We interpret this as a signal of the onset of superconductivity., Comment: 46 pages, 17 figures

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45. The Self‐Tuning of the Cosmological Constant and the Holographic Relaxion

Author

Lukas T. Witkowski, Yuta Hamada, Francesco Nitti, Elias Kiritsis, AstroParticule et Cosmologie (APC (UMR_7164)), Observatoire de Paris, PSL Research University (PSL)-PSL Research University (PSL)-Université Paris Diderot - Paris 7 (UPD7)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Centre National de la Recherche Scientifique (CNRS), Institut d'Astrophysique de Paris (IAP), Institut national des sciences de l'Univers (INSU - CNRS)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Observatoire de Paris, Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Centre National de la Recherche Scientifique (CNRS)-Université de Paris (UP), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Centre National de la Recherche Scientifique (CNRS)-Université Paris Cité (UPCité), Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Centre National de la Recherche Scientifique (CNRS)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Observatoire de Paris, and PSL Research University (PSL)-PSL Research University (PSL)-Université Paris Diderot - Paris 7 (UPD7)

Subjects
High Energy Physics - Theory, brane-world models, membrane model: action, electroweak interaction: symmetry breaking, FOS: Physical sciences, General Physics and Astronomy, Cosmological constant, hierarchy, solution: static, Higgs sector, Standard Model, vacuum state, 03 medical and health sciences, Theoretical physics, High Energy Physics::Theory, High Energy Physics - Phenomenology (hep-ph), Brane cosmology, Axion, 030304 developmental biology, Physics, 0303 health sciences, gauge-gravity duality, cosmological constant, gravitation: duality, [PHYS.HTHE]Physics [physics]/High Energy Physics - Theory [hep-th], 030302 biochemistry & molecular biology, Electroweak interaction, High Energy Physics::Phenomenology, stability, High Energy Physics - Phenomenology, High Energy Physics - Theory (hep-th), Higgs particle: mass, axion, [PHYS.HPHE]Physics [physics]/High Energy Physics - Phenomenology [hep-ph], Higgs boson, holography, Brane
Abstract

We propose a brane-world setup based on gauge/gravity duality that permits the simultaneous realisation of self-tuning of the cosmological constant and a stabilisation of the electroweak hierarchy. The Standard Model dynamics including the Higgs sector is confined to a flat 4-dimensional brane, embedded in a 5-dimensional bulk whose dynamics is governed by Einstein-dilaton-axion gravity. The inclusion of a dynamical bulk axion is new compared to previous implementations of the self-tuning mechanism. Because of the presence of the axion, the model generically exhibits a multitude of static solutions, with different values for the equilibrium position for the brane. Under mild assumptions regarding the dependence of brane parameters on bulk fields, a number of these solutions exhibit electroweak symmetry breaking with a hierarchically small Higgs mass as compared to the cutoff-scale of the brane theory. The realisation of self-tuning of the cosmological constant is generic and as efficient as in previous constructions without a bulk axion. Vacua with a hierarchically small Higgs mass can sometimes be found, regardless of whether the brane theory depends explicitly on the bulk axion. Because it is expected on general principles that the brane action will depend on the axion, the generation of solutions with a large hierarchy is a robust feature., 78 pages, 16 figures; several additional explanations added and a stability analysis for the scalars performed (v2)

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46. Aspects of Holographic Renormalization Group Flows on Curved Manifolds

Author

Ghosh, Jewel Kumar, AstroParticule et Cosmologie (APC (UMR_7164)), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Observatoire de Paris, Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Centre National de la Recherche Scientifique (CNRS)-Université de Paris (UP), Université Sorbonne Paris Cité, Elias Kiritsis, Francesco Nitti, and Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Centre National de la Recherche Scientifique (CNRS)-Université Paris Cité (UPCité)

Subjects
Holographie, Monde de Brane, Curvature, [PHYS.PHYS]Physics [physics]/Physics [physics], Holography, Transition de phase, Dualité Gauge/Gravité, RG flows, Brane-world, Courbure, Gauge/Gravity duality, AdS/CFT, Flux RG, Phase transition
Abstract

The Anti-de Sitter (AdS)/Conformal Field Theory (CFT) correspondence, also known as holographic duality, is a remarkable connection between string theory (which includes gravity) and gauge theories. It relates a CFT in a d-dimensional space-time to a gravity theory in higher dimensional space-time which is also referred to as the bulk. The latter has a boundary on which the conformal eld theory may be thought to reside. In this thesis, the subject of study is the holographic description of Renormalization Group (RG) fows of (field) theories on maximally symmetric space-times. The theoretical framework I used is Einstein-scalar theory. Inclusion of the dynamical scalar field corresponds to breaking boundary conformal invariance. In this work, both the boundary and bulk slices are chosen to be maximally symmetric space-times and the evolution of bulk fields is studied. It describes holographic RG flows on curved manifolds. Furthermore, two applications are presented in this thesis. The first application is in the context of F-theorems and the second is regarding a curved defect in the bulk holographic RG flows.F-theorems for Quantum Field Theories (QFT) defined on 3-dimensional space-times demand the existence of so-called F-functions. These are monotonically decreasing functions along the RG flow. In this work, new F-functions for holographic theories have been found which are constructed from the on-shell action of a holographic RG flow solution on a 3-sphere. They allow an entropic interpretation, therefore providing a direct connection between the entropic formulation of the F-theorem and its definition in terms of free energy. The second application of holographic RG flows explored in this thesis is in the context of models displaying a self-tuning mechanism as a proposed resolution of the cosmological constant (CC) problem. In these models, our 4-dimensional universe is realized as a brane embedded in a 5-dimensional bulk. This framework allows solutions where the brane geometry is flat despite of the presence of non-trivial vacuum energy on its worldvolume. This is referred to as self-tuning. On each side of the brane, the solutions are holographic RG flows. The new aspect introduced in this thesis is to use the holographic RG flows on curved manifolds, which in turn allows the study of self-tuning solutions where the brane is also curved.; La correspondance CFT (Anti-De Sitter) (AdS) / Théorie des champs conformes (CFT), également connue sous le nom de dualité holographique, constitue un lien remarquable entre la théorie des cordes (qui inclut la gravité) et les théories de jauge. Elle relie une CFT dans un espace-temps d-dimensionnel à une théorie de la gravité dans un espace-temps dimension supérieur, également appelé bloc. Ce dernier a une limite dans laquelle réside la théorie du champ conforme.Dans cette thèse, le sujet d'étude est la description holographique des flux de groupes de renormalisation (RG) des théories (de champ) sur les espaces-temps à symétrie maximale. Le cadre théorique que j'ai utilisé est la théorie d'Einstein-scalaire. L'inclusion du champ scalaire dynamique correspond à la rupture de l'invariance conforme aux limites. Dans ce travail, les limites et les tranches du bloc sont choisies pour être des espaces-temps à symétrie maximale et l'évolution des champs en bloc est étudiée. Il décrit les écoulements RG holographiques sur des variétés courbes. De plus, deux applications sont présentées dans cette thèse. La première application s'inscrit dans le contexte des théorèmes F et la seconde concerne un défaut incurvé dans les flux RG holographiques en masse.Les théorèmes F pour les théories de champs quantiques (QFT) définies dans des espaces-temps tridimensionnels exigent l'existence de fonctions dites F. Ce sont des fonctions décroissantes de façon monotone le long du flux RG. Dans ce travail, de nouvelles fonctions F pour les théories holographiques ont été découvertes. Elles sont construites à partir de l'action sur la parois d'une solution de flux holographique RG sur une sphère à 3-sphères. Ils permettent une interprétation entropique, fournissant ainsi un lien direct entre la formulation entropique du théorème F et sa définition en termes d’énergie libre.La deuxième application des flux RG holographiques explorée dans cette thèse se situe dans le contexte de modèles affichant un mécanisme d'auto-ajustement en tant que résolution proposée du problème de la constante cosmologique (CC). Dans ces modèles, notre univers à 4-dimensions est réalisé comme une brane intégrée dans un volume à 5-dimensions. Ce cadre permet des solutions où la géométrie de la brane est plate malgré la présence d'une énergie de vide non triviale sur son worldvolume. Ceci est appelé réglage automatique. De chaque côté de la brane, les solutions sont des flux RG holographiques. Le nouvel aspect introduit dans cette thèse consiste à utiliser les flux RG holographiques sur des variétés courbes, ce qui permet à son tour d’étudier des solutions à réglage automatique dans lesquelles la brane est également courbe.

Published
2019

47. Aspects lies aux flux de groupes derenormalisation holographique sur des collecteurs courbes

Author

Ghosh, Jewel Kumar, AstroParticule et Cosmologie (APC (UMR_7164)), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Observatoire de Paris, Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Centre National de la Recherche Scientifique (CNRS)-Université de Paris (UP), Université Sorbonne Paris Cité, Elias Kiritsis, and Francesco Nitti

Subjects
Holographie, Monde de Brane, Curvature, [PHYS.PHYS]Physics [physics]/Physics [physics], Holography, Transition de phase, Dualité Gauge/Gravité, RG flows, Brane-world, Courbure, Gauge/Gravity duality, AdS/CFT, Flux RG, Phase transition
Abstract

The Anti-de Sitter (AdS)/Conformal Field Theory (CFT) correspondence, also known as holographic duality, is a remarkable connection between string theory (which includes gravity) and gauge theories. It relates a CFT in a d-dimensional space-time to a gravity theory in higher dimensional space-time which is also referred to as the bulk. The latter has a boundary on which the conformal eld theory may be thought to reside. In this thesis, the subject of study is the holographic description of Renormalization Group (RG) fows of (field) theories on maximally symmetric space-times. The theoretical framework I used is Einstein-scalar theory. Inclusion of the dynamical scalar field corresponds to breaking boundary conformal invariance. In this work, both the boundary and bulk slices are chosen to be maximally symmetric space-times and the evolution of bulk fields is studied. It describes holographic RG flows on curved manifolds. Furthermore, two applications are presented in this thesis. The first application is in the context of F-theorems and the second is regarding a curved defect in the bulk holographic RG flows.F-theorems for Quantum Field Theories (QFT) defined on 3-dimensional space-times demand the existence of so-called F-functions. These are monotonically decreasing functions along the RG flow. In this work, new F-functions for holographic theories have been found which are constructed from the on-shell action of a holographic RG flow solution on a 3-sphere. They allow an entropic interpretation, therefore providing a direct connection between the entropic formulation of the F-theorem and its definition in terms of free energy. The second application of holographic RG flows explored in this thesis is in the context of models displaying a self-tuning mechanism as a proposed resolution of the cosmological constant (CC) problem. In these models, our 4-dimensional universe is realized as a brane embedded in a 5-dimensional bulk. This framework allows solutions where the brane geometry is flat despite of the presence of non-trivial vacuum energy on its worldvolume. This is referred to as self-tuning. On each side of the brane, the solutions are holographic RG flows. The new aspect introduced in this thesis is to use the holographic RG flows on curved manifolds, which in turn allows the study of self-tuning solutions where the brane is also curved.; La correspondance CFT (Anti-De Sitter) (AdS) / Théorie des champs conformes (CFT), également connue sous le nom de dualité holographique, constitue un lien remarquable entre la théorie des cordes (qui inclut la gravité) et les théories de jauge. Elle relie une CFT dans un espace-temps d-dimensionnel à une théorie de la gravité dans un espace-temps dimension supérieur, également appelé bloc. Ce dernier a une limite dans laquelle réside la théorie du champ conforme.Dans cette thèse, le sujet d'étude est la description holographique des flux de groupes de renormalisation (RG) des théories (de champ) sur les espaces-temps à symétrie maximale. Le cadre théorique que j'ai utilisé est la théorie d'Einstein-scalaire. L'inclusion du champ scalaire dynamique correspond à la rupture de l'invariance conforme aux limites. Dans ce travail, les limites et les tranches du bloc sont choisies pour être des espaces-temps à symétrie maximale et l'évolution des champs en bloc est étudiée. Il décrit les écoulements RG holographiques sur des variétés courbes. De plus, deux applications sont présentées dans cette thèse. La première application s'inscrit dans le contexte des théorèmes F et la seconde concerne un défaut incurvé dans les flux RG holographiques en masse.Les théorèmes F pour les théories de champs quantiques (QFT) définies dans des espaces-temps tridimensionnels exigent l'existence de fonctions dites F. Ce sont des fonctions décroissantes de façon monotone le long du flux RG. Dans ce travail, de nouvelles fonctions F pour les théories holographiques ont été découvertes. Elles sont construites à partir de l'action sur la parois d'une solution de flux holographique RG sur une sphère à 3-sphères. Ils permettent une interprétation entropique, fournissant ainsi un lien direct entre la formulation entropique du théorème F et sa définition en termes d’énergie libre.La deuxième application des flux RG holographiques explorée dans cette thèse se situe dans le contexte de modèles affichant un mécanisme d'auto-ajustement en tant que résolution proposée du problème de la constante cosmologique (CC). Dans ces modèles, notre univers à 4-dimensions est réalisé comme une brane intégrée dans un volume à 5-dimensions. Ce cadre permet des solutions où la géométrie de la brane est plate malgré la présence d'une énergie de vide non triviale sur son worldvolume. Ceci est appelé réglage automatique. De chaque côté de la brane, les solutions sont des flux RG holographiques. Le nouvel aspect introduit dans cette thèse consiste à utiliser les flux RG holographiques sur des variétés courbes, ce qui permet à son tour d’étudier des solutions à réglage automatique dans lesquelles la brane est également courbe.

Published
2019

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