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We present a new supersymmetric index for three-dimensional N = 2 gauge theories defined on Σ × S 1 , where Σ is a spindle, with twist or anti-twist for the R -symmetry background gauge field. We start examining general supersymmetric backgrounds of Euclidean new minimal supergravity admitting two Killing spinors of opposite R -charges. We then focus on Σ × S 1 and demostrate how to realise twist and anti-twist. We compute the supersymmetric partition functions on such backgrounds via localization and show that these are captured by a general formula, depending on the type of twist, which unifies and generalises the superconformal and topologically twisted indices. [ABSTRACT FROM AUTHOR]

Using the supergravity dual and the plane-wave limit as a guide, we conjecture the asymptotic large coupling form of the Hagedorn temperature for planar super Yang-Mills to order 1 / λ . This is two orders beyond the presently known behavior. Using the quantum spectral curve procedure of Harmark and Wilhelm, we show that our conjectured form is in excellent agreement with the numerical results. [ABSTRACT FROM AUTHOR]

We extend the Cecotti–Kallosh model of Starobinsky inflation in supergravity by adding a holomorphic function to the superpotential in order to generate a large peak in the power spectrum of scalar (curvature) perturbations. In our approach, the singular non-canonical kinetic terms are largely responsible for inflation (as an attractor solution), whereas the superpotential is engineered to generate a production of PBH. We study the cases with (a) a linear holomorphic function, (b) a quadratic holomorphic function, and (c) an exponential holomorphic function, as regards the dependence of inflation and PBH production upon parameters of those functions and initial conditions, as well as verify viability of inflation with our superpotentials. We find that an efficient production of PBH consistent with cosmic microwave background measurements is only possible in the second (b) case. We calculate the masses of the produced PBH and find that they are below the Hawking (black hole) evaporation limit, so that they cannot be part of the current dark matter in our Universe. [ABSTRACT FROM AUTHOR]

We classify all warped dS 5 backgrounds in D  = 11 supergravity with enhanced supersymmetry. We show that backgrounds preserving N  = 16 supersymmetries consist of either a stack of M5 branes with transverse space R 5 , or a generalized M5-brane configuration with transverse space R × N 4 , where N 4 is a hyper-Kähler manifold and the M5-brane harmonic function is determined by a hyper-Kähler potential on N 4. Moreover, we find that there are no backgrounds preserving exactly N  = 24 supersymmetries. Backgrounds preserving N  = 32 supersymmetries correspond to either R 1 , 10 or A d S 7 × S 4 . [ABSTRACT FROM AUTHOR]

Starting with Witten's twistor string, chiral string theories have emerged that describe field theory amplitudes without the towers of massive states of conventional strings. These models are known as ambitwistor strings due to their target space; the space of complexified null geodesics, also called ambitwistor space. Correlators in these string theories directly yield compact formulæ for tree-level amplitudes and loop integrands, in the form of worldsheet integrals fully localized on solutions to constraints known as the scattering equations. In this chapter, we discuss two incarnations of the ambitwistor string: a 'vector representation' starting in space–time and structurally resembling the Ramond Neveu–Schwarz (RNS) superstring, and a four-dimensional twistorial version closely related to, but distinct from Witten's original model. The RNS-like models exist for several theories, with 'heterotic' and type II models describing super-Yang–Mills and 10d supergravities respectively, and they manifest the double copy relations directly at the level of the worldsheet models. In the second half of the chapter, we explain how the underlying models lead to diverse applications, ranging from extensions to new sectors of theories, loop amplitudes and to scattering on curved backgrounds. We conclude with a brief discussion of connections to conventional strings and celestial holography. [ABSTRACT FROM AUTHOR]

The post-Minkowskian expansion of Einstein's general theory of relativity has received much attention in recent years due to the possibility of harnessing the computational power of modern amplitude calculations in such a classical context. In this brief review, we focus on the post-Minkowskian expansion as applied to the two-body problem in general relativity without spin, and we describe how relativistic quantum field theory can be used to greatly simplify analytical calculations based on the Einstein–Hilbert action. Subtleties related to the extraction of classical physics from such quantum mechanical calculations highlight the care which must be taken when both positive and negative powers of Planck's constant are at play. In the process of obtaining classical results in both Einstein gravity and supergravity, one learns new aspects of quantum field theory that are obscured when using units in which Planck's constant is set to unity. The scattering amplitude approach provides a self-contained framework for deriving the two-body scattering valid in all regimes of energy. There is hope that the full impact of amplitude computations in this field may significantly alter the way in which gravitational wave predictions will advance in the coming years. [ABSTRACT FROM AUTHOR]

In this paper we study the rotationally invariant harmonic cohomology of a two-parameter family of Einstein metrics g which admits a cohomogeneity one action of SU (2) Ă— U (1) and has AdS asymptotics. Depending on the values of the parameters, g is either of NUT type, if the fixed-point locus of the U (1) action is zero-dimensional, or of bolt type, if it is two-dimensional. We find that if g is of NUT type then the space of SU (2)-invariant harmonic two-forms is three-dimensional and consists entirely of self-dual forms; if g is of bolt type it is four-dimensional. In both cases we explicitly determine a basis. The pair (g, F) for F a self-dual harmonic two-form is also a solution of the bosonic sector of 4 D supergravity. We determine for which choices it is a supersymmetric solution and the amount of preserved supersymmetry. [ABSTRACT FROM AUTHOR]

We determine the necessary and sufficient conditions for warped product dS n solutions, 5 ⩽ n ⩽ 10, to preserve supersymmetry in D = 11 supergravity, without assuming factorization of the Killing spinors. We prove that for 7 ⩽ n ⩽ 10, all such solutions are flat, with vanishing four-form. We also show that the only warped product dS 6 solutions are either the maximally supersymmetric AdS 7 × S 4 solution, or R 1 , 6 × N 4 where N 4 is hyperKähler, with vanishing four-form. Supersymmetric warped product dS 5 solutions are then classified; it is shown that all such solutions are generalized M5-brane configurations, for which the transverse space is R × N 4 , and N 4 is a hyperKähler manifold. If the four-form is covariantly constant, then N 4 admits a hyperKähler potential. [ABSTRACT FROM AUTHOR]

Some time ago, we showed that a weak (linear) massless spin two wave could only propagate on a Ricci-flat or Ricci-constant background: it must necessarily be a perturbation of general relativity. This was just the continuation of the higher spin chain: massless s = 3/2 also required Ricci-flatness (which is the basis of supergravity) while s > 2 needs Riemann flatness. This note, entitled ‘higher spin m ≠0 excitations on curved backgrounds and cosmological supergravity’, re-analyzes the problem in a perhaps more physical way: by considering massless andâ€"only apparentlyâ€"massive small excitations and showing how their parameters relate to the cosmological constant. We will thus prove, in a simple physical way, the necessity, as well as the sufficiency, of the known supergravity results. [ABSTRACT FROM AUTHOR]

That supergravity can refine grains is verified in many materials. However, the underlying mechanism is still an open question. Although some convincing theories have been proposed, including the ‘crystal rain’ theory and the dendrite fragmentation theory, there is a lack of solid evidence, especially from the atomic scale. Based on the presetting nucleuses method, this study investigates the motion and growth behaviors of nucleuses during the solidification process of Al melt under supergravity condition with molecular dynamics simulation. It is found that supergravity builds a gradient pressure in the samples along the direction of supergravity, and the gradient pressure results in the gradient distribution of sample density. The preset nucleuses move directionally along the direction of supergravity forming ‘crystal rain’, while their directional moving velocity decreases due to the increase of buoyancy, which is caused by the increase of melt density in the motion path of the nucleuses. The supergravity-induced pressure not only decreases the critical size of nucleuses but also increases the growth velocity of nucleuses. The research results also indicate that larger nucleuses grow much faster than smaller ones at the same pressure. Owing to the gradient distribution of pressure, the nucleuses grow much faster along the direction of supergravity than other directions and evolve into an ‘inverted cone’ shape. Therefore, these findings show that supergravity can change the nucleation, motion and growth of nucleuses by establishing a gradient pressure in the melt, thus affecting the microstructure of the casting. Our results provide solid support for the ‘crystal rain’ theory and the nucleation rate rising theory from atomic scale.

We write down the algebraic Bethe ansatz for string theory on AdS3 × S3 × T4 and AdS3 × S3 × K3 in its orbifold limits. We use it to determine the wave-functions of protected closed strings in these backgrounds and prove that their energies are protected to all orders in α′. We further apply the ABA to find the wave functions of protected states of AdS3 × S3 × S3 × S1 and its Z 2 orbifold. Our findings match with protected spectrum calculations from supergravity, SymN orbifolds and apply to the complete moduli space of these theories, excluding orbifold blow-up modes for which further analysis is necessary. [ABSTRACT FROM AUTHOR]

We prove that any supersymmetric solution to five-dimensional minimal gauged supergravity with SU(2) symmetry, that is timelike outside an analytic horizon, is a Gutowski–Reall black hole or its near-horizon geometry. The proof combines a delicate near-horizon analysis with the general form for a Kähler metric with cohomogeneity-1 SU(2) symmetry. We also prove that any timelike supersymmetric soliton solution to this theory, with SU(2) symmetry and a nut or a complex bolt, has a Kähler base with enhanced U(1) × SU(2) symmetry, and we exhibit a family of asymptotically Ad solitons for p ⩾ 3 with a bolt in this class. [ABSTRACT FROM AUTHOR]

We compute the first-order α′ corrections to a general family of supersymmetric heterotic backgrounds which describes a rotating superposition of a fundamental string and a momentum wave. We focus on a particular solution within this family that gives rise, upon dimensional reduction to five dimensions, to a black ring with two charges and one dipole that has a singular horizon with vanishing area in the supergravity approximation, better known as small black ring. We show that the singularity at the horizon persists even after the first-order α′ corrections have been taken into account. This would imply that, contrarily to what has been argued in the literature, higher-derivative corrections do not resolve the singular horizon of the five-dimensional small black ring, at least at first order in α′ expansion. [ABSTRACT FROM AUTHOR]

This article is an introduction to two research programs that are currently very active, the conformal bootstrap and scattering amplitudes. Rather than attempting full surveys, the emphasis is on common ideas and methods shared by these two seemingly very different programs. In both fields, mathematical and physical constraints are placed directly on the physical observables in order to explore the landscape of possible consistent quantum field theories (QFTs). We give explicit examples from both programs: the reader can expect to encounter boiling water, ferromagnets, pion scattering, and emergent symmetries on this journey into the landscape of local relativistic QFTs. The first part is written for a general physics audience. The second part includes further details, including a new on-shell bottom-up reconstruction of the model with the Fubini–Study metric arising from resummation of the n-point interaction terms derived from amplitudes. The presentation is an extended version of a colloquium given at the Aspen Center for Physics in August 2019. [ABSTRACT FROM AUTHOR]

We consider a new inflationary model in which an antisymmetric tensor field Aνρσ and its four-form field strength Fμνρσ = 4∂[μAνρσ] are coupled to the scalar sector of the standard model and to the Ricci scalar. The four-form field induces modifications to the Higgs self-coupling constant, the cosmological constant, and the non-minimal coupling constant, which results in the modification to the inflaton potential. We also show that there is no need for the Higgs-gravity coupling in the presence of four-form gravity interaction, but still can produce the right amount of density perturbation for inflation. [ABSTRACT FROM AUTHOR]

The covariant Noether charge formalism (also known as the covariant phase method) of Wald and collaborators, including its cohomological extension, is a manifestly covariant Hamiltonian formalism that, in principle, allows one to define and compute the energy, angular momenta, and chemical potentials of generic solutions of gravitational theories. However, it has been observed that for some supergravity solutions the variation of the Noether charge is not (at least manifestably) integrable, and as a result it is unclear whether there are well-defined thermodynamic charges for these solutions. In this work, we derive an expression for the variation of the covariant Noether charges for any solution of type IIB 10-dimensional supergravity or 11-dimensional supergravity. Although this Noether quantity is not integrable in general, we show that for asymptotically scale-invariant solutions, it is. In particular, the asymptotic scale-invariance allows one to define an energy density and conjugate chemical potentials which obey a first law of thermodynamics and a Smarr relation. These two thermodynamic relations can then be shown to imply that the variation of the Noether charge is integrable, and accordingly the energy and other thermodynamic charges may be defined unambiguously. We explicitly demonstrate and illustrate our claim by computing the thermodynamic charges of two non-trivial supergravity solutions that were recently constructed: (1) the Polchinski–Strassler black brane that is dual to the deconfined phase of theory, and (2) the CGLP black brane that asymptotes to the mass deformed Cvetič–Gibbons–Lü–Pope (CGLP) solution. [ABSTRACT FROM AUTHOR]

In the present work, we explore several gravitational aspects such as energy extraction (via the Penrose process and superradiance), particle collisions around a , U(1)2 rotating dyonic black hole (BH) in the gauged supergravity model. The influence of the rotation parameter (a) and the gauge coupling constant (g) on the behavior of the horizon and ergoregion of the BH is investigated. In comparison to the extremal Kerr BH, the gauge coupling constant, under certain constraints, can interestingly enhance the maximum efficiency of energy extraction through the Penrose process by almost twice. Under the same constraints, we can extract approximately 60.75% of the initial mass-energy from the BH which is noticeably higher and far different from that of the Kerr BH. The limit of energy extraction in terms of the local speeds of the fragments is also determined with the help of the Wald inequality. We discover an upper limit on the gauge coupling constant up to which superradiance is likely to occur. Finally, we estimate the center-of-mass energy (ECM) of two particles with the same rest mass moving in the equatorial plane of the BH. Our study also aims to sensitize ECM to the parameters a and g for both extremal and nonextremal spacetime. Especially, for the extremal case, an infinitely large amount of ECM can be achieved closer to the event horizon confirming a basic point of view that an extreme supergravity BH with dyons could serve as ultimate particle accelerators as compared to Kerr and any other generalized BHs in this family and other alternative theories of gravity. However, ECM for the nonextremal spacetime is shown to be finite and has an upper bound. [ABSTRACT FROM AUTHOR]

Integrable deformations of type IIB superstring theory on AdS5 × S5 have played an important role over the last years. The Yang–Baxter deformation is a systematic way of generating such integrable deformations. Since its introduction, this topic has seen important conceptual progress and has among others led to the intriguing discovery generalized supergravity, a new low-energy effective theory. This review endeavors to not only introduce the historical development of the Yang–Baxter deformation, but also its relation to generalized supergravity, non-geometric backgrounds, non-abelian T-duality and preserved Killing spinors. We supplement the general treatment with a wealth of explicit examples. [ABSTRACT FROM AUTHOR]

Attractor black holes in type II string compactifications on K3 × T2 are in correspondence with equivalence classes of binary quadratic forms. The discriminant of the quadratic form governs the black hole entropy, and the count of attractor black holes at a given entropy is given by a class number. Here, we show this tantalizing relationship between attractors and arithmetic can be generalized to a rich family, connecting black holes in supergravity and string models with analogous equivalence classes of more general forms under the action of arithmetic groups. Many of the physical theories involved have played an earlier role in the study of 'magical' supergravities, while their mathematical counterparts are directly related to geometry-of-numbers examples in the work of Bhargava et al. This paper is dedicated to the memory of Peter Freund. The last section is devoted to some of MG's personal reminiscences of Peter Freund. [ABSTRACT FROM AUTHOR]

In the last few years, there has been significant interest in understanding the stationary comparison version of the first law of black hole mechanics in the vielbein formulation of gravity. Several authors have pointed out that to discuss the first law in the vielbein formulation one must extend the Iyer–Wald Noether charge formalism appropriately. Jacobson and Mohd (2015 Phys. Rev. D 92 124010) and Prabhu (2017 Class. Quantum Grav. 34 035011) formulated such a generalisation for symmetry under combined spacetime diffeomorphisms and local Lorentz transformations. In this paper, we apply and appropriately adapt their formalism to four-dimensional gravity coupled to a Majorana field and to a Rarita–Schwinger field. We explore the first law of black hole mechanics and the construction of the Lorentz-diffeomorphism Noether charges in the presence of fermionic fields, relevant for simple supergravity. [ABSTRACT FROM AUTHOR]

A manifestly diffeomorphism invariant exact renormalization group requires extra diffeomorphism invariant ultraviolet regularisation at some effective cutoff scale Λ. This motivates construction of a 'Parisi-Sourlas' supergravity, in analogy with the gauge theory case, where the superpartner fields have the wrong spin-statistics such that they can become Pauli–Villars regulator fields after spontaneous symmetry breaking. We show that in contrast to gauge theory, the free theory around flat space is already non-trivial and in a sense already displays some spontaneous symmetry breaking. We show that the fluctuating fields form multiplets whose mass matrices imply that the fields propagate into each other not only with the expected 1/p2 but also through propagators with improved ultraviolet properties, namely 1/p4 and 1/p6, despite the fact that the action contains a maximum of two space-time derivatives. [ABSTRACT FROM AUTHOR]

We present explicit examples of supergravity solutions corresponding to backreacting localised (non-intersecting) O6 planes in flux reductions of massive IIA supergravity and address some criticism towards the very existence of such solutions. We verify in detail how the smeared orientifold solution becomes a good approximation to the localised solution in the large volume/weak coupling limit, as expected. We also find an exotic solution where prior to backreaction the internal space has a boundary and when backreaction is included the boundary disappears and the space closes off. The exotic example is however outside of the supergravity approximation everywhere. [ABSTRACT FROM AUTHOR]

In this paper we extend previous work on the relation between the complex structure moduli of the underlying Calabi–Yau manifold in five dimensional supergravity with the time evolution of an embedded 3-brane. We numerically solve the fields' equations for such a construction and focus on dust and radiation filled branes; with the possible application of modeling the Universe as a brane-world. It is shown that in both cases the time evolution of the moduli causally connects to the expansion of the brane-world. We also find that in most cases considered there is an early short period of rapid accelerative expansion, indicating an inflationary epoch. We report on these results; leaving analysis of the underlying causes for future work. [ABSTRACT FROM AUTHOR]

The maximally supersymmetric Freund–Rubin vacua for 11 dimensional supergravity, namely AdS4 × S7 and AdS7 × S4, admit an analytic continuation to S4 × S7. From the full harmonic expansions on S4 × S7, it is shown that by analytical continuation to either AdS4, or to AdS7, the detailed structure of the Kaluza–Klein spectrum can be obtained for both vacua in a unified manner. The results are shown to be related by a simple rule which interchanges the spacetime and internal space representations. We also obtain the linearized field equations for the singletons and doubletons but they can be gauged away by fixing certain Stuckelberg shift symmetries inherited from the Kaluza–Klein reduction. [ABSTRACT FROM AUTHOR]

The maximally supersymmetric Freund–Rubin vacua for 11 dimensional supergravity, namely AdS4 × S7 and AdS7 × S4, admit an analytic continuation to S4 × S7. From the full harmonic expansions on S4 × S7, it is shown that by analytical continuation to either AdS4, or to AdS7, the detailed structure of the Kaluza–Klein spectrum can be obtained for both vacua in a unified manner. The results are shown to be related by a simple rule which interchanges the spacetime and internal space representations. We also obtain the linearized field equations for the singletons and doubletons but they can be gauged away by fixing certain Stuckelberg shift symmetries inherited from the Kaluza–Klein reduction. [ABSTRACT FROM AUTHOR]

It is well known that linearized gravity in spacetimes with compact Cauchy surfaces and continuous symmetries suffers from linearization instabilities: solutions to classical linearized gravity in such a spacetime must satisfy so-called linearization stability conditions (or constraints) for them to extend to solutions in the full non-linear theory. Moncrief investigated implications of these conditions in linearized quantum gravity in such background spacetimes and found that the quantum linearization stability constraints lead to the requirement that all physical states must be invariant under the symmetries generated by these constraints. He studied these constraints for linearized quantum gravity in flat spacetime with the spatial sections of toroidal topology in detail. Subsequently, his result was reproduced by the method of group-averaging. In this paper the quantum linearization stability conditions are studied for simple supergravity in this spacetime. In addition to the linearization stability conditions corresponding to the spacetime symmetries, i.e. spacetime translations, there are also fermionic linearization stability conditions corresponding to the background supersymmetry. We construct all states satisfying these quantum linearization stability conditions, including the fermionic ones, and show that they are obtained by group-averaging over the supergroup of the global supersymmetry of this theory. [ABSTRACT FROM AUTHOR]

We apply the Lie algebra expansion method to the super-Poincaré algerba in four dimensions. We define a set of p-brane projectors that induce a decomposition of the super-Poincaré algebra preparatory for the expansion. We show that starting from the supergravity action in four dimensions it is possible to obtain non-relativistic supersymmetric theories, describing strings or membranes. [ABSTRACT FROM AUTHOR]

This paper presents a series of constructions providing 11-dimensional bosonic supergravity backgrounds. In particular, we treat Lorentzian manifolds given in terms of twisted products of six-dimensional Lorentzian manifolds and five-dimensional Riemannian manifolds. By considering a representative flux 4-form adapted to this setting, we analyse the system of bosonic supergravity equations and describe the corresponding geometric constraints. The new supergravity backgrounds appear for special cases associated to the adapted flux 4-form. For example, we provide a relation of 11-dimensional supergravity with Ricci-isotropic Walker manifolds, and illustrate several results in their terms and in terms of Ricci-flat Riemannian manifolds. [ABSTRACT FROM AUTHOR]

Remembering the foundational contributions of Peter Freund to supergravity, and especially to the problems of dimensional compactification, reduction is considered with a non-compact space transverse to the lower dimensional theory. The known problem of a continuum of Kaluza–Klein states is avoided here by the occurrence of a mass gap between a single normalizable zero-eigenvalue transverse wavefunction and the edge of the transverse state continuum. This style of reduction does not yield a formally consistent truncation to the lower dimensional theory, so developing the lower-dimensional effective theory requires integrating out the Kaluza–Klein states lying above the mass gap. [ABSTRACT FROM AUTHOR]

We describe a methodology for testing no-scale supergravity by the LAT instrument onboard the Fermi Space Telescope via observation of gamma ray emissions from lightest supersymmetric (SUSY) neutralino annihilations. For our test vehicle we engage the framework of the SUSY grand unified model no-scale flipped SU(5) with extra vector-like flippon multiplets derived from F-theory, known as -SU(5). We show that through compression of the light stau and light bino neutralino mass difference, where internal bremsstrahlung photons give a dominant contribution, the photon yield from annihilation of SUSY dark matter can be elevated to a number of events potentially observable by the Fermi-LAT in the coming years. Likewise, the increased yield in no-scale -SU(5) may also have rendered the existing observation of a 133 GeV monochromatic gamma ray line visible, if additional data should exclude systematic or statistical explanations. The question of intensity aside, no-scale -SU(5) can indeed provide a natural weakly interacting massive particle candidate with a mass in the correct range to yield γγ and γZ emission lines at mχ ∼ 133 GeV and mχ ∼ 145 GeV, respectively. Additionally, we elucidate the emerging empirical connection between recent Planck satellite data and no-scale supergravity cosmological models which mimic the Starobinsky model of inflation. Together, these experiments furnish rich alternate avenues for testing no-scale -SU(5), and similarly structured models, the results of which may lend independent credence to observations made at the Large Hadron Collider. [ABSTRACT FROM AUTHOR]

A compact formulation of the field-strengths, Bianchi identities and gauge transformations for tensor hierarchies in gauged maximal supergravity theories is given. A key role in the construction is played by the recently-introduced tensor hierarchy algebra. [ABSTRACT FROM AUTHOR]

We consider a model of D-dimensional supergravity coupled to elementary p-branes. We use gravitational arguments to deduce the low energy effective theory of N nearly parallel branes. This is a (p + 1)-dimensional scalar field theory, where the scalars represent the positions of the branes in their transverse space. We propose that the same theory in a certain temperature regime describes a ‘soup’ of strongly interacting branes, giving a microscopic description of near extremal black p-branes. We use natural approximations to estimate the energy density of this soup as a function of the physical parameters; N, temperature, brane tension and gravitational coupling. We also characterize the horizon radius, measured in the metric natural to the branes, with the thermal vev of the scalars. For both quantities we find agreement with the corresponding supergravity black brane results. Surprisingly, beyond the physical parameters, we are naturally able to reproduce certain irrational factors such as πs. We comment on how these ideas may explain why black hole thermodynamics arises in gauge theories with holographic duals at finite temperature. [ABSTRACT FROM AUTHOR]

The gravity coupling of the symmetric space sigma model is studied in the solvable Lie algebra parametrization. The corresponding Einstein equations are derived and the energy–momentum tensor is calculated. The results are used to derive the dynamical equations of the warped five-dimensional (5D) geometry for localized bulk scalar interactions in the framework of thick brane world models. The Einstein and scalar field equations are derived for flat brane geometry in the context of minimal and non-minimal gravity-bulk scalar couplings. [ABSTRACT FROM AUTHOR]

We construct non-extremal as well as extremal black string solutions in minimal five-dimensional supergravity coupled to vector multiplets using dimensional reduction to three Euclidean dimensions. Our method does not assume that the scalar manifold is a symmetric space, and applies as well to a class of non-supersymmetric theories governed by a generalization of special real geometry. We find that five-dimensional black string solutions correspond to geodesics in a specific totally geodesic para-Kähler submanifold of the scalar manifold of the dimensionally reduced theory, and identify the subset of geodesics that corresponds to regular black string solutions in five dimensions. Extremal solutions are distinguished by whether or not the corresponding geodesics are along the eigendirections of the para-complex structure, which for supersymmetric theories reduces to the usual notion of BPS and non-BPS solutions. For non-extremal black strings the values of the scalars at the outer and inner horizon are not independent integration constants but determined by certain functions of the charges and moduli. By lifting solutions from three to four dimensions we obtain non-extremal versions of small black holes, and find that while the outer horizon takes finite size, the inner horizon is still degenerate. [ABSTRACT FROM AUTHOR]

We describe and study families of BPS microstate geometries, namely, smooth, horizonless asymptotically flat solutions to supergravity. We examine these solutions from the perspective of earlier attempts to find solitonic solutions in gravity and show how the microstate geometries circumvent the earlier ‘no-go’ theorems. In particular, we re-analyze the Smarr formula and show how it must be modified in the presence of non-trivial second homology. This, combined with the supergravity Chern–Simons terms, allows the existence of rich classes of BPS, globally hyperbolic, asymptotically flat, microstate geometries whose spatial topology is the connected sum of N copies of S2 × S2 with a ‘point at infinity’ removed. These solutions also exhibit ‘evanescent ergo-regions,’ that is, the non-space-like Killing vector guaranteed by supersymmetry is time-like everywhere except on time-like hypersurfaces (ergo-surfaces) where the Killing vector becomes null. As a by-product of our work, we are able to resolve the puzzle of why some regular soliton solutions violate the BPS bound: their spacetimes do not admit a spin structure. [ABSTRACT FROM AUTHOR]

We describe the most general asymptotically flat, stationary, non-extremal, dyonic black hole of the four-dimensional supergravity coupled to three vector multiplets that describes the low-energy regime of the STU model. Under U-dualities, this can be used as a seed to generate all single-centered stationary black holes of supergravity. The independent conserved charges are the mass, angular momentum, four electric charges and four magnetic charges; an independent NUT charge can also be added. Several aspects of the black hole are presented, including thermodynamics, the BPS limit, the near-horizon limit in the extremal fast and slow rotating cases, properties of black hole horizons, the existence of Killing tensors and the separability of probe scalars. [ABSTRACT FROM AUTHOR]

We obtain the first black hole solution to Type-IIA String Theory compactified on an arbitrary self-mirror Calabi–Yau manifold in the presence of non-perturbative quantum corrections. Remarkably enough, the solution involves multivalued functions, which could lead to a violation of the No-Hair conjecture. We discuss how String Theory forbids such scenario. However, the possibility still remains open in the context of four-dimensional ungauged Supergravity. [ABSTRACT FROM AUTHOR]

The global U-dualities of extended supergravity have played a central role in differentiating the distinct classes of extremal black hole solutions. When the U-duality group satisfies certain algebraic conditions, as is the case for a broad class of supergravities, the extremal black holes enjoy a further symmetry known as Freudenthal duality (F-duality), which although distinct from U-duality preserves the Bekenstein–Hawking entropy. Here it is shown that, by adopting the doubled Lagrangian formalism, F-duality, defined on the doubled field strengths, is not only a symmetry of the black hole solutions, but also of the equations of motion themselves. A further role for F-duality is introduced in the context of world-sheet actions. The Nambu–Goto world-sheet action in any (t, s) signature spacetime can be written in terms of the F-dual. The corresponding field equations and Bianchi identities are then related by F-duality allowing for an F-dual formulation of Gaillard–Zumino duality on the world-sheet. An equivalent polynomial ‘Polyakov-type’ action is introduced using the so-called black hole potential. Such a construction allows for actions invariant under all groups of type E7, including E7 itself, although in this case the stringy interpretation is less clear. [ABSTRACT FROM AUTHOR]

Based on the structure of the on-shell linearized superspace of type IIB supergravity, we argue that there is a non-BPS 16 derivative interaction in the effective action of type IIB string theory of the form (t8t8R4)2, which we call the interaction. It lies in the same supermultiplet as the interaction. Using the Kawai–Lewellen–Tye relation, we analyze the structure of the tree level eight-graviton scattering amplitude in the type IIB theory, which leads to the interaction at the linearized level. This involves an analysis of color-ordered multi-gluon disc amplitudes in the type I theory, which shows an intricate pole structure and transcendentality consistent with various other interactions. Considerations of S-duality show that the interaction receives non-analytic contributions in the string coupling at one and two loops. Apart from receiving perturbative contributions, we show that the interaction receives a non-vanishing contribution in the one D-instanton-anti-instanton background at leading order in the weak coupling expansion. [ABSTRACT FROM AUTHOR]

We construct a supersymmetric extension of three-dimensional Newton–Cartan gravity by gauging a super-Bargmann algebra. In order to obtain a non-trivial supersymmetric extension of the Bargmann algebra one needs at least two supersymmetries leading to a super-Bargmann algebra. Due to the fact that there is a universal Newtonian time, only one of the two supersymmetries can be gauged. The other supersymmetry is realized as a fermionic Stueckelberg symmetry and only survives as a global supersymmetry. We explicitly show how, in the frame of a Galilean observer, the system reduces to a supersymmetric extension of the Newton potential. The corresponding supersymmetry rules can only be defined, provided we also introduce a ‘dual Newton potential’. We comment on the four-dimensional case. [ABSTRACT FROM AUTHOR]

We give a complete classification of supersymmetric gravitational instantons in Euclidean N = 2 supergravity coupled to vector multiplets. An interesting class of solutions is found which corresponds to the Euclidean analogue of stationary black hole solutions of N = 2 supergravity theories. [ABSTRACT FROM AUTHOR]

In this paper we elucidate the rigid limit of N = 2 supergravity coupled to vector and hypermultiplets. In particular we show how the respective scalar field spaces reduce to their global counterparts. In the hypermultiplet sector we focus on the relation between the local and rigid c-map. [ABSTRACT FROM AUTHOR]

We study the relation between 5D super Yang-Mills theory and the holographic description of 6D (2, 0) superconformal theory. We start by clarifying some issues related to the localization of N = 1 SYM with matter on S5. We concentrate on the case of a single adjoint hypermultiplet with a mass term and argue that the theory has a symmetry enlargement at mass M = 1/(2r), where r is the S5 radius. However, in order to have a well-defined localization locus it is necessary to rotate M onto the imaginary axis, breaking the enlarged symmetry. Based on our prescription, the imaginary mass values are physical and we show how the localized path integral is consistent with earlier results for 5D SYM in flat space.We then compute the free energy and the expectation value for a circular Wilson loop in the large N limit. The Wilson loop calculation shows a mass dependent constant rescaling between weak and strong coupling. The Wilson loop continued back to to the enlarged symmetry point is consistent with a supergravity computation for an M2 brane using the standard identification of the compactification radius and the 5D coupling. If we continue back to the physical regime and use this value of the mass to determine the compactification radius, then we find agreement between the SYM free energy and the corresponding supergravity calculation. We also verify numerically some of our analytic approximations. [ABSTRACT FROM AUTHOR]

We study the relation between 5D super Yang-Mills theory and the holographic description of 6D (2, 0) superconformal theory. We start by clarifying some issues related to the localization of N = 1 SYM with matter on S5. We concentrate on the case of a single adjoint hypermultiplet with a mass term and argue that the theory has a symmetry enlargement at mass M = 1/(2r), where r is the S5 radius. However, in order to have a well-defined localization locus it is necessary to rotate M onto the imaginary axis, breaking the enlarged symmetry. Based on our prescription, the imaginary mass values are physical and we show how the localized path integral is consistent with earlier results for 5D SYM in flat space.We then compute the free energy and the expectation value for a circular Wilson loop in the large N limit. The Wilson loop calculation shows a mass dependent constant rescaling between weak and strong coupling. The Wilson loop continued back to to the enlarged symmetry point is consistent with a supergravity computation for an M2 brane using the standard identification of the compactification radius and the 5D coupling. If we continue back to the physical regime and use this value of the mass to determine the compactification radius, then we find agreement between the SYM free energy and the corresponding supergravity calculation. We also verify numerically some of our analytic approximations. [ABSTRACT FROM AUTHOR]