56 results on '"Málek P"'
Search Results
2. Symmetry reduction of gravitational Lagrangians
- Author
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Frausto, Guillermo, Kolář, Ivan, Málek, Tomáš, and Torre, Charles
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General Relativity and Quantum Cosmology ,High Energy Physics - Theory - Abstract
We analyze all possible symmetry reductions of Lagrangians that yield fully equivalent field equations for any 4-dimensional metric theory of gravity. Specifically, we present a complete list of infinitesimal group actions obeying the principle of symmetric criticality, identify the corresponding invariant metrics (and $l$-chains), discuss relations among them, and analyze simplifications allowed by the residual diffeomorphism group and Noether identities before and after variation of the reduced Lagrangian. We employ rigorous treatment of the symmetry reduction by Fels and Torre and use the Hicks classification of infinitesimal group actions by means of Lie algebras pairs of isometries and their isotropy subalgebras. The classification is recast in the coordinates in which the well-known symmetries and geometries are easily recognizable and relatable to each other. The paper is accompanied by a code for the symmetry reduction of Lagrangians that we developed in \texttt{xAct} package of \textsc{Mathematica}., Comment: 32 pages, 2 figures, 10 tables, an example in Sec. VI.G and various typos corrected, comments welcome! more...
- Published
- 2024
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3. Cubic and higher-order supergravity couplings for AdS vacua using Exceptional Field Theory
- Author
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Duboeuf, Bastien, Malek, Emanuel, and Samtleben, Henning
- Subjects
High Energy Physics - Theory ,General Relativity and Quantum Cosmology - Abstract
We show how to use Exceptional Field Theory to efficiently compute $n$-point couplings of all Kaluza-Klein modes for vacua that can be uplifted from maximal gauged supergravities to 10/11 dimensions via a consistent truncation. Via the AdS/CFT correspondence, these couplings encode the $n$-point functions of holographic conformal fields theories. Our methods show that these $n$-point couplings are controlled by the $n$-point invariant of scalar harmonics of the maximally symmetric point of the truncation, allowing us to show that infinitely-many $n$-point couplings vanish for any vacua of the truncation, even though they may be allowed by the remnant symmetry group of the vacua. This gives new results even for the maximally supersymmetric AdS$_5 \times S^5$, AdS$_4 \times S^7$ and AdS$_7 \times S^4$ vacua of string and M-theory, where we prove old conjectures about the vanishing of $n$-point extremal and near-extremal couplings. Focusing in particular on cubic couplings for vacua of 5-dimensional gauged supergravity, we derive explicit universal formulae encoding these couplings for any vacuum within a consistent truncation. We use this to compute known and new couplings involving spin-0, spin-1, spin-2 for the AdS$_5 \times S^5$ vacuum of IIB string theory., Comment: 25 pages more...
- Published
- 2023
4. Y-algebroids and $E_{7(7)} \times \mathbb{R}^+$-generalised geometry
- Author
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Hulik, Ondrej, Malek, Emanuel, Valach, Fridrich, and Waldram, Daniel
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High Energy Physics - Theory ,Mathematical Physics ,Mathematics - Differential Geometry - Abstract
We define the notion of Y-algebroids, generalising the Lie, Courant, and exceptional algebroids that have been used to capture the local symmetry structure of type II string theory and M-theory compactifications to $D \geq 5$ dimensions. Instead of an invariant inner product, or its generalisation arising in exceptional algebroids, Y-algebroids are built around a specific type of tensor, denoted $Y$, that provides exactly the necessary properties to also describe compactifications to $D=4$ dimensions. We classify "M-exact" $E_7$-algebroids and show that this precisely matches the form of the generalised tangent space of $E_{7(7)} \times \mathbb{R}^+$-generalised geometry, with possible twists due to 1-, 4- and 7-form fluxes, corresponding physically to the derivative of the warp factor and the M-theory fluxes. We translate the notion of generalised Leibniz parallelisable spaces, relevant to consistent truncations, into this language, where they are mapped to so-called exceptional Manin pairs. We also show how to understand Poisson-Lie U-duality and exceptional complex structures using Y-algebroids., Comment: 20 pages, accepted version more...
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- 2023
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5. Propagators in AdS for higher-derivative and nonlocal gravity: Heat kernel approach
- Author
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Kolář, Ivan and Málek, Tomáš
- Subjects
General Relativity and Quantum Cosmology ,High Energy Physics - Theory - Abstract
We present a new covariant method of construction of the (position space) propagators in the $N$-dimensional (Euclidean) anti-de Sitter background for any gravitational theory with the Lagrangian that is an analytic expression in the metric, curvature, and covariant derivative. We show that the propagators (in Landau gauge) for all such theories can be expressed using the heat kernels for scalars and symmetric transverse-traceless rank-2 tensors on the hyperbolic $N$-space. The latter heat kernels are constructed explicitly and shown to be directly related to the former if an improved bi-scalar representation is used. Our heat kernel approach is first tested on general relativity, where we find equivalent forms of the propagators. Then it is used to obtain explicit expressions for propagators for various higher-derivative as well as infinite-derivative/nonlocal theories of gravity. As a by-product, we also provide a new derivation of the equivalent action (correcting a mistake in the original derivation) and an extension of the quadratic action to arbitrary ${N\geq 3}$ dimensions., Comment: 35 pages, typos corrected, minor changes in the text (mainly introduction and conclusions), title changed more...
- Published
- 2023
6. Infinite derivative gravity resolves nonscalar curvature singularities
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Kolář, Ivan and Málek, Tomáš
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General Relativity and Quantum Cosmology ,High Energy Physics - Theory - Abstract
We explicitly demonstrate that the nonlocal ghost-free ultraviolet modification of general relativity (GR) known as the infinite derivative gravity (IDG) resolves nonscalar curvature singularities in exact solutions of the full theory. We analyze exact pp-wave solutions of GR and IDG describing gravitational waves generated by null radiation. Curvature of GR and IDG solutions with the same energy-momentum tensor is compared in parallel-propagated frames along timelike and null geodesics at finite values of the affine parameter. While the GR pp-wave solution contains a physically problematic nonscalar curvature singularity at the location of the source, the curvature of its IDG counterpart is finite., Comment: 5 pages, 1 figure more...
- Published
- 2023
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7. Adding fluxes to consistent truncations: IIB supergravity on ${\rm AdS}_3 \times S^3 \times S^3 \times S^1$
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Eloy, Camille, Galli, Michele, and Malek, Emanuel
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High Energy Physics - Theory ,General Relativity and Quantum Cosmology - Abstract
We use $E_{8(8)}$ Exceptional Field Theory to construct the consistent truncation of IIB supergravity on $S^3 \times S^3 \times S^1$ to maximal 3-dimensional ${\cal N}=16$ gauged supergravity containing the ${\cal N}=(4,4)$ AdS$_3$ vacuum. We explain how to achieve this by adding a 7-form flux to the $S^1$ reduction of the dyonic $E_{7(7)}$ truncation on $S^3 \times S^3$ previously constructed in the literature. Our truncation Ansatz includes, in addition to the ${\cal N}=(4,4)$ vacuum, a host of moduli breaking some or all of the supersymmetries. We explicitly construct the uplift of a subset of these to construct new supersymmetric and non-supersymmetric AdS$_3$ vacua of IIB string theory, which include a range of perturbatively stable non-supersymmetric 10-d vacua. Moreover, we show how the supersymmetric direction of the moduli space of AdS$_3$ vacua of six-dimensional gauged supergravity studied in arXiv:2111.01167 is compactified upon lifting to 10 dimensions, and find evidence of T-duality playing a role in global aspects of the moduli space. Along the way, we also derive the form of 3-dimensional ${\cal N}=16$ gauged supergravity in terms of the embedding tensor and rule out a 10-/11-dimensional origin of some 3-dimensional gauged supergravities., Comment: 31 pages more...
- Published
- 2023
8. A holographic RG flow from the squashed to the round $S^7$
- Author
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Duboeuf, Bastien, Galli, Michele, Malek, Emanuel, and Samtleben, Henning
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High Energy Physics - Theory - Abstract
We construct and analyze the domain wall solution in $D=11$ supergravity connecting the $N=1$, AdS$_4\times S_{\rm squashed}^7$ vacuum to the $N=8$, AdS$_4\times S_{\rm round}^7$ vacuum. This domain wall describes the holographic renormalization group flow from an ${\rm Sp}(2)\times {\rm Sp}(1)$ symmetric UV fixed point to the ${\rm SO}(8)$ symmetric IR fixed point. It breaks all supersymmetries which are (partially) restored at its endpoints. We show how recent techniques from exceptional field theory allow us to compute the quadratic couplings of all Kaluza-Klein fluctuations around the domain wall background, encoding all two-point correlators along the holographic RG flow., Comment: 19 pages, 6 figures more...
- Published
- 2023
9. Kaluza-Klein Spectrometry beyond Consistent Truncations: The Squashed $S^7$
- Author
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Duboeuf, Bastien, Malek, Emanuel, and Samtleben, Henning
- Subjects
High Energy Physics - Theory ,General Relativity and Quantum Cosmology - Abstract
We show how to use Exceptional Field Theory to compute the full Kaluza-Klein spectra of 10- and 11-dimensional supergravity around deformations of backgrounds of maximal gauged supergravity by scalar modes that do not form part of the consistent truncation. This includes deformations of AdS$_4 \times S^7$ and AdS$_5 \times S^5$ by modes that are not part of the ${\cal N}=8$ supermultiplet. As an application, we compute the full Kaluza-Klein spectrum of the ${\cal N}=1$ and ${\cal N}=0$ squashed $S^7$. In this example, all conformal dimensions are captured by a universal formula in terms of the Casimir operators and additional quantum numbers which organise the spectrum., Comment: 27 pages. v2: minor changes and added fermionic spectra of ${\cal N}=0$ squashed $S^7$. v3: typos corrected more...
- Published
- 2022
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10. Consistent truncations to 3-dimensional supergravity
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Galli, Michele and Malek, Emanuel
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High Energy Physics - Theory ,General Relativity and Quantum Cosmology - Abstract
We show how to construct consistent truncations of 10-/11-dimensional supergravity to 3-dimensional gauged supergravity, preserving various amounts of supersymmetry. We show, that as in higher dimensions, consistent truncations can be defined in terms of generalised $G$-structures in Exceptional Field Theory, with $G \subset E_{8(8)}$ for the 3-dimensional case. Differently from higher dimensions, the generalised Lie derivative of $E_{8(8)}$ Exceptional Field Theory requires a set of "covariantly constrained" fields to be well-defined, and we show how these can be constructed from the $G$-structure itself. We prove several general features of consistent truncations, allowing us to rule out a higher-dimensional origin of many 3-dimensional gauged supergravities. In particular, we show that the compact part of the gauge group can be at most $\mathrm{SO}(9)$ and that there are no consistent truncations on a 7-or 8-dimensional product of spheres such that the full isometry group of the spheres is gauged. Moreover, we classify which matter-coupled ${\cal N} \geq 4$ gauged supergravities can arise from consistent truncations. Finally, we give several examples of consistent truncations to three dimensions. These include the truncations of IIA and IIB supergravity on $S^7$ leading to two different ${\cal N}=16$ gauged supergravites, as well as more general IIA/IIB truncations on $H^{p,7-p}$. We also show how to construct consistent truncations on compactifications of IIB supergravity on $S^5$ fibred over a Riemann surface. These result in 3-dimensional ${\cal N}=4$ gauged supergravities with scalar manifold ${\cal M} = \frac{\mathrm{SO}(6,4)}{\mathrm{SO}(6) \times \mathrm{SO}(4)} \times \frac{\mathrm{SU}(2,1)}{\mathrm{S}(\mathrm{U}(2)\times\mathrm{U}(1))}$ with a $\mathrm{ISO}(3)\times\mathrm{U}(1)^4$ gauging and for hyperboloidal Riemann surfaces contain ${\cal N}=(2,2)$ AdS$_3$ vacua., Comment: 33 pages plus appendix more...
- Published
- 2022
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11. Romans massive QP manifolds
- Author
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Arvanitakis, Alex S., Malek, Emanuel, and Tennyson, David
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High Energy Physics - Theory - Abstract
We introduce QP manifolds that capture the generalised geometry of type IIA string backgrounds with Ramond-Ramond fluxes and Romans mass. Each of these is associated to a BPS brane in type IIA: a D2, D4, or NS5-brane. We explain how these probe branes are related to their associated QP-manifolds via the AKSZ topological field theory construction and the recent brane phase space construction. M-theory/type IIA duality is realised on the QP-manifold side as symplectic reduction along the M-theory circle (for branes that do not wrap it); this always produces IIA QP-manifolds with vanishing Romans mass., Comment: V2 - References and discussion added more...
- Published
- 2022
12. Holographic Evidence for Non-Supersymmetric Conformal Manifolds
- Author
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Giambrone, Alfredo, Guarino, Adolfo, Malek, Emanuel, Samtleben, Henning, Sterckx, Colin, and Trigiante, Mario
- Subjects
High Energy Physics - Theory - Abstract
We provide the first holographic evidence for the existence of a non-supersymmetric conformal manifold arising from exactly marginal but supersymmetry-breaking deformations of a superconformal three-dimensional field theory. In particular, we construct a 2-parameter non-supersymmetric deformation of a supersymmetric AdS non-geometric background in Type IIB string theory. We prove that the non-supersymmetric backgrounds are perturbatively stable and also do not suffer from various non-perturbative instabilities. Finally, we argue that diffeomorphism symmetry protects our solutions against higher-derivative string corrections., Comment: 6 pages. v2: clarifications added, published version more...
- Published
- 2021
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13. The higher-dimensional origin of five-dimensional $\boldsymbol{{\cal N}\!=\!2}$ gauged supergravities
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Josse, Gregoire, Malek, Emanuel, Petrini, Michela, and Waldram, Daniel
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High Energy Physics - Theory ,General Relativity and Quantum Cosmology - Abstract
Using exceptional generalised geometry, we classify which five-dimensional ${\cal N}=2$ gauged supergravities can arise as a consistent truncation of 10-/11-dimensional supergravity. Exceptional generalised geometry turns the classification into an algebraic problem of finding subgroups $G_S \subset \mathrm{USp}(8) \subset \mathrm{E}_{6(6)}$ that preserve exactly two spinors. Moreover, the intrinsic torsion of the $G_S$ structure must contain only constant singlets under $G_S$, and these, in turn, determine the gauging of the five-dimensional theory. The resulting five-dimensional theories are strongly constrained: their scalar manifolds are necessarily symmetric spaces and only a small number of matter multiplets can be kept, which we completely enumerate. We also determine the largest reductive and compact gaugings that can arise from consistent truncations., Comment: 61 pages more...
- Published
- 2021
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14. Exact gyratons in higher and infinite derivative gravity
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Kolář, Ivan, Málek, Tomáš, Dengiz, Suat, and Kilicarslan, Ercan
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General Relativity and Quantum Cosmology ,High Energy Physics - Theory - Abstract
We study solutions describing spinning null sources called gyratons in generic theories of gravity with terms that are quadratic in curvature and contain an arbitrary number of covariant derivatives. In particular, we show that the properties of pp-waves of the algebraic type III allow for extreme simplification of the field equations. It turns out that the resulting differential equations are exactly solvable due to partial decoupling and linearity of the equations. This is demonstrated explicitly by finding axially symmetric gyraton solutions in Stelle's fourth derivative gravity and the non-local gravity with an infinite number of derivatives., Comment: 28 pages, 2 figures, comments welcome! more...
- Published
- 2021
- Full Text
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15. Global Properties of the Conformal Manifold for S-Fold Backgrounds
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Giambrone, Alfredo, Malek, Emanuel, Samtleben, Henning, and Trigiante, Mario
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High Energy Physics - Theory - Abstract
We study a one-parameter family of $\mathcal{N}=2$ anti-de Sitter vacua with ${\rm U}(1)^2$ symmetry of gauged four-dimensional maximal supergravity, with dyonic gauge group $[{\rm SO}(6)\times {\rm SO}(1,1)]\ltimes \mathbb{R}^{12}$. These backgrounds are known to correspond to Type IIB S-fold solutions with internal manifold of topology $S^1\times S^5$. The family of AdS$_4$ vacua is parametrized by a modulus $\chi$. Although $\chi$ appears non-compact in the four-dimensional supergravity, we show that this is just an artefact of the four-dimensional description. We give the 10-dimensional geometric interpretation of the modulus and show that it actually has periodicity of $\frac{2\pi}{T}$, which is the inverse radius of $S^1$. We deduce this by providing the explicit $D=10$ uplift of the family of vacua as well as computing the entire modulus-dependent Kaluza-Klein spectrum as a function of $\chi$. At the special values $\chi=0$ and $\chi=\frac{\pi}{T}$, the symmetry enhances according to ${\rm U}(1)^2\rightarrow{\rm U}(2)$, giving rise however to inequivalent Kaluza-Klein spectra. At $\chi=\frac{\pi}{T}$, this realizes a bosonic version of the "space invaders" scenario with additional massless vector fields arising from formerly massive fields at higher Kaluza-Klein levels., Comment: 33 pages, 1 figure, subsections 4.2.1 and 5.4.1 added in which the symmetry properties of the spectrum with respect to the chi parameter is discussed in detail; typos corrected more...
- Published
- 2021
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16. Exact solutions of non-local gravity in a class of almost universal spacetimes
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Kolář, Ivan, Málek, Tomáš, and Mazumdar, Anupam
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General Relativity and Quantum Cosmology ,High Energy Physics - Theory - Abstract
We study exact solutions of the infinite derivative gravity with null radiation which belong to the class of almost universal Weyl type III/N Kundt spacetimes. This class is defined by the property that all rank-2 tensors ${B_{ab}}$ constructed from the Riemann tensor and its covariant derivatives have traceless part of type N of the form $\mathcal{B}(\square)S_{ab}$ and the trace part constantly proportional to the metric. Here, $\mathcal{B}(\square)$ is an analytic operator and $S_{ab}$ is the traceless Ricci tensor. We show that the convoluted field equations reduce to a single non-local but linear equation, which contains only the Laplace operator $\triangle$ on 2-dimensional spaces of constant curvature. Such a non-local linear equation is always exactly solvable by eigenfunction expansion or using the heat kernel method for the non-local form-factor $\exp(-\ell^2\triangle)$ (with $\ell$ being the length scale of non-locality) as we demonstrate on several examples. We find the non-local analogues of the Aichelburg--Sexl and the Hotta--Tanaka solutions, which describe gravitational waves generated by null sources propagating in Minkowski, de Sitter, and anti-de Sitter spacetimes. They reduce to the solutions of the local theory far from the sources or in the local limit, ${\ell\to0}$. In the limit ${\ell\to\infty}$, they become conformally flat. We also discuss possible hints suggesting that the non-local solutions are regular at the locations of the sources in contrast to the local solutions; all curvature components in the natural null frame are finite and specifically the Weyl components vanish., Comment: 22 pages, 3 figures, comments welcome! more...
- Published
- 2021
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17. Consistent truncations around half-maximal AdS$_5$ vacua of 11-dimensional supergravity
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Malek, Emanuel and Camell, Valentí Vall
- Subjects
High Energy Physics - Theory ,General Relativity and Quantum Cosmology - Abstract
We use exceptional field theory to systematically study all possible consistent truncations around half-maximal AdS$_5$ vacua of M-theory. We show that only truncations with at most three vector multiplets are consistent. The possible gaugings are SU(2)$\times$U(1) and ISO(3)$\times$U(1) where, in the first case, the U(1) factor can have different embeddings inside the global symmetry group SO$(5,n)$, where $n \leq 3$ equals the number of vector multiplets. We show that the ISO(3)$\times$U(1) truncation only exists around vacua that are locally an $S^4$ fibration over a Riemann surface, and argue that this is the only consistent truncation with vector multiplets around these vacua that can be constructed by going through the 7-dimensional SO(5) gauged supergravity obtained after an $S^4$ reduction. The consistent truncations with SU(2)$\times$U(1) gaugings with vector multiplets exist only if certain conditions are satisfied, which we derive., Comment: 46 pages more...
- Published
- 2020
18. Kaluza-Klein Spectroscopy for the Leigh-Strassler SCFT
- Author
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Bobev, Nikolay, Malek, Emanuel, Robinson, Brandon, Samtleben, Henning, and van Muiden, Jesse
- Subjects
High Energy Physics - Theory - Abstract
We apply recently developed tools from exceptional field theory to calculate the full Kaluza-Klein spectrum of the AdS$_5$ Pilch-Warner solution of type IIB supergravity. Through the AdS/CFT correspondence this yields detailed information about the spectrum of protected and unprotected operators of the four-dimensional $\mathcal{N}=1$ Leigh-Strassler SCFT, in the planar limit. We also calculate explicitly the superconformal index of the SCFT in this limit and show that it agrees precisely with the spectrum of protected operators in the supergravity calculation., Comment: 47 pages, v2: minor typos fixed more...
- Published
- 2020
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19. Stable non-supersymmetric Anti-de Sitter vacua of massive IIA supergravity
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Guarino, Adolfo, Malek, Emanuel, and Samtleben, Henning
- Subjects
High Energy Physics - Theory ,General Relativity and Quantum Cosmology - Abstract
Stable non-supersymmetric Anti-de Sitter (AdS) vacua of string theory are widely believed not to exist. In this letter, we analytically compute the full bosonic Kaluza-Klein spectrum around the ${\rm G_2}$-invariant non-supersymmetric $\textrm{AdS}_4$ solution of massive IIA supergravity, and show that it is perturbatively stable. We also provide evidence that six other non-supersymmetric $\textrm{AdS}_4$ solutions of massive IIA supergravity are perturbatively stable. Since previous studies have indicated that these AdS vacua may also be non-perturbatively stable, our findings pose a challenge to the Swampland Conjecture., Comment: 6 pages, 1 figure; v2: published version, minor changes, references added more...
- Published
- 2020
- Full Text
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20. Kaluza-Klein Spectrometry from Exceptional Field Theory
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Malek, Emanuel and Samtleben, Henning
- Subjects
High Energy Physics - Theory ,General Relativity and Quantum Cosmology - Abstract
Exceptional field theories yield duality-covariant formulations of higher-dimensional supergravity. They have proven to be an efficient tool for the construction of consistent truncations around various background geometries. In this paper, we demonstrate how the formalism can moreover be turned into a powerful tool for computing the Kaluza-Klein mass spectra around these backgrounds. Most of these geometries have little to no remaining symmetries and their spectra are accessible to standard methods only in selected subsectors. The present formalism not only grants access to the full Kaluza-Klein spectra but also provides the scheme to identify the resulting mass eigenstates in higher dimensions. As a first illustration, we rederive in compact form the mass spectrum of IIB supergravity on $S^5$. We further discuss the application of our formalism to determine the mass spectra of higher Kaluza-Klein multiplets around the warped geometries corresponding to some prominent ${\cal N}=2$ and ${\cal N}=0$ AdS vacua in maximal supergravity., Comment: 45 pages; v2: published version with minor typos corrected more...
- Published
- 2020
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21. E$_{6(6)}$ Exceptional Drinfel'd Algebras
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Malek, Emanuel, Sakatani, Yuho, and Thompson, Daniel C.
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High Energy Physics - Theory ,General Relativity and Quantum Cosmology - Abstract
The exceptional Drinfel'd algebra (EDA) is a Leibniz algebra introduced to provide an algebraic underpinning with which to explore generalised notions of U-duality in M-theory. In essence it provides an M-theoretic analogue of the way a Drinfel'd double encodes generalised T-dualities of strings. In this note we detail the construction of the EDA in the case where the regular U-duality group is $E_{6(6)}$. We show how the EDA can be realised geometrically as a generalised Leibniz parallelisation of the exceptional generalised tangent bundle for a six-dimensional group manifold $G$, endowed with a Nambu-Lie structure. When the EDA is of coboundary type, we show how a natural generalisation of the classical Yang-Baxter equation arises. The construction is illustrated with a selection of examples including some which embed Drinfel'd doubles and others that are not of this type., Comment: 27 pages more...
- Published
- 2020
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22. Tachyonic Kaluza-Klein modes and the AdS swampland conjecture
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Malek, Emanuel, Nicolai, Hermann, and Samtleben, Henning
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High Energy Physics - Theory ,General Relativity and Quantum Cosmology - Abstract
We compute the Kaluza-Klein spectrum of the non-supersymmetric SO(3)$\,\times\,$SO(3)-invariant AdS$_4$ vacuum of 11-dimensional supergravity, whose lowest-lying Kaluza-Klein modes belong to a consistent truncation to 4-dimensional ${\cal N}=8$ supergravity and are stable. We show that, nonetheless, the higher Kaluza-Klein modes become tachyonic so that this non-supersymmetric AdS$_4$ vacuum is perturbatively unstable within 11-dimensional supergravity. This represents the first example of unstable higher Kaluza-Klein modes and provides further evidence for the AdS swampland conjecture, which states that there are no stable non-supersymmetric AdS vacua within string theory. We also find 27 infinitesimal moduli amongst the Kaluza-Klein modes, which hints at the existence of a family of non-supersymmetric AdS$_4$ vacua., Comment: 22 pages; v2 published version with minor changes more...
- Published
- 2020
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23. Kaluza-Klein Spectrometry for Supergravity
- Author
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Malek, Emanuel and Samtleben, Henning
- Subjects
High Energy Physics - Theory ,General Relativity and Quantum Cosmology - Abstract
Exceptional field theories yield duality covariant formulations of supergravity. We show that they provide a highly efficient tool to compute the Kaluza-Klein mass spectra associated to compactifications around various background geometries relevant for string theory and holographic applications. This includes geometries with little to no remaining symmetries, hardly accessible to standard methods. As an illustration, we work out the masses of some higher Kaluza-Klein multiplets around warped geometries corresponding to some prominent ${\cal N} = 2$ supersymmetric AdS vacua in maximal supergravity., Comment: 6 pages; v2: published version with minor changes in text more...
- Published
- 2019
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24. Poisson-Lie U-duality in Exceptional Field Theory
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Malek, Emanuel and Thompson, Daniel C.
- Subjects
High Energy Physics - Theory - Abstract
Poisson-Lie duality provides an algebraic extension of conventional Abelian and non-Abelian target space dualities of string theory and has seen recent applications in constructing quantum group deformations of holography. Here we demonstrate a natural upgrading of Poisson-Lie to the context of M-theory using the tools of exceptional field theory. In particular, we propose how the underlying idea of a Drinfeld double can be generalised to an algebra we call an exceptional Drinfeld algebra. These admit a notion of "maximally isotropic subalgebras" and we show how to define a generalised Scherk-Schwarz truncation on the associated group manifold to such a subalgebra. This allows us to define a notion of Poisson-Lie U-duality. Moreover, the closure conditions of the exceptional Drinfeld algebra define natural analogues of the cocycle and co-Jacobi conditions arising in Drinfeld double. We show that upon making a further coboundary restriction to the cocycle that an M-theoretic extension of Yang-Baxter deformations arise. We remark on the application of this construction as a solution-generating technique within supergravity., Comment: 20 pages; v2: minor changes made, references added more...
- Published
- 2019
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25. Open-String Non-Associativity in an R-flux Background
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Lust, Dieter, Malek, Emanuel, Plauschinn, Erik, and Syvari, Marc
- Subjects
High Energy Physics - Theory - Abstract
We derive the commutation relations for open-string coordinates on D-branes in non-geometric background spaces. Starting from D0-branes on a three-dimensional torus with H-flux, we show that open strings with end points on D3-branes in a three-dimensional R-flux background exhibit a non-associative phase-space algebra, which is similar to the non-associative R-flux algebra of closed strings. Therefore, the effective open-string gauge theory on the D3-branes is expected to be a non-associative gauge theory. We also point out differences between the non-associative phase space structure of open and closed strings in non-geometric backgrounds, which are related to the different structure of the world-sheet commutators of open and closed strings., Comment: 29 pages; v2: added section 3.5, minor changes; v3: published version, clarifications added in sections 3 and 4, added appendix B.4 more...
- Published
- 2019
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26. Supersymmetric AdS$_7$ and AdS$_6$ vacua and their consistent truncations with vector multiplets
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Malek, Emanuel, Samtleben, Henning, and Camell, Valentí Vall
- Subjects
High Energy Physics - Theory ,General Relativity and Quantum Cosmology - Abstract
Using exceptional field theory we construct supersymmetric warped AdS$_7$ vacua of massive IIA and AdS$_6$ vacua of IIB, as well as their consistent truncations including vector multiplets. We show there are no consistent truncations of massive IIA supergravity around its supersymmetric AdS$_7$ vacua with vector multiplets when the Roman's mass is non-vanishing. For AdS$_6$ vacua of IIB supergravity, we find that in addition to the consistent truncation to pure $\mathrm{F}(4)$ gauged SUGRA, the only other half-maximal truncations that are consistent result in $\mathrm{F}(4)$ gauged SUGRA coupled to one or two Abelian vector multiplets, to three non-Abelian vector multiplets, leading to an $\mathrm{ISO}(3)$ gauged SUGRA, or to three non-Abelian plus one Abelian vector multiplet, leading to an $\mathrm{ISO}(3) \times \mathrm{U}(1)$ gauged SUGRA. These consistent truncations with vector multiplets exist when the two holomorphic functions that define the AdS$_6$ vacua satisfy certain differential conditions which we derive. We use these to deduce that no globally regular AdS$_6$ solutions admit a consistent truncation to $\mathrm{F}(4)$ gauged SUGRA with two vector multiplets, and show that the Abelian T-dual of the Brandhuber-Oz vacuum allows a consistent truncation to $\mathrm{F}(4)$ gauged SUGRA with a single vector multiplet., Comment: 58 pages plus appendices more...
- Published
- 2019
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27. Almost universal spacetimes in higher-order gravity theories
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Kuchynka, Martin, Málek, Tomáš, Pravda, Vojtěch, and Pravdová, Alena
- Subjects
General Relativity and Quantum Cosmology ,High Energy Physics - Theory - Abstract
We study almost universal spacetimes - spacetimes for which the field equations of any generalized gravity with the Lagrangian constructed from the metric, the Riemann tensor and its covariant derivatives of arbitrary order reduce to one single differential equation and one algebraic condition for the Ricci scalar. We prove that all d-dimensional Kundt spacetimes of Weyl type III and traceless Ricci type N are almost universal. Explicit examples of Weyl type II almost universal Kundt metrics are also given. The considerable simplification of the field equations of higher-order gravity theories for almost universal spacetimes is then employed to study new Weyl type II, III, and N vacuum solutions to quadratic gravity in arbitrary dimension and six-dimensional conformal gravity. Necessary conditions for almost universal metrics are also studied., Comment: 17 pages, final version, to appear in Phys. Rev. D more...
- Published
- 2018
- Full Text
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28. Supersymmetric AdS$_{7}$ and AdS$_6$ vacua and their minimal consistent truncations from exceptional field theory
- Author
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Malek, Emanuel, Samtleben, Henning, and Camell, Valentí Vall
- Subjects
High Energy Physics - Theory ,General Relativity and Quantum Cosmology - Abstract
We show how to construct supersymmetric warped AdS$_7$ vacua of massive IIA and AdS$_6$ vacua of IIB supergravity, using "half-maximal structures" of exceptional field theory. We use this formalism to obtain the minimal consistent truncations around these AdS vacua., Comment: 20 pages more...
- Published
- 2018
- Full Text
- View/download PDF
29. A No-go Theorem for a Gauge Vector as a Space-time Goldstone
- Author
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Klein, Remko, Malek, Emanuel, Roest, Diederik, and Stefanyszyn, David
- Subjects
High Energy Physics - Theory ,General Relativity and Quantum Cosmology - Abstract
Scalars and fermions can arise as Goldstone modes of non-linearly realised extensions of the Poincare group (with important implications for the soft limits of such theories): the Dirac-Born-Infeld scalar realises a higher-dimensional Poincare symmetry, while the Volkov-Akulov fermion corresponds to super-Poincare. In this paper we classify extensions of the Poincare group which give rise to a vector Goldstone mode instead. Our main result is that there are no healthy interacting $U(1)$ gauge theories that non-linearly realise space-time symmetries beyond gauge transformations. This implies that the special soft limits of e.g. the Born-Infeld vector cannot be explained by space-time symmetries., Comment: 6 pages; v2: minor changes more...
- Published
- 2018
- Full Text
- View/download PDF
30. O-folds: Orientifolds and Orbifolds in Exceptional Field Theory
- Author
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Blair, Chris D. A., Malek, Emanuel, and Thompson, Daniel C.
- Subjects
High Energy Physics - Theory ,General Relativity and Quantum Cosmology - Abstract
We describe conventional orientifold and orbifold quotients of string and M-theory in a unified approach based on exceptional field theory (ExFT). Using an extended spacetime, ExFT combines all the maximal ten and eleven dimensional supergravities into a single theory manifesting a global symmetry corresponding to the exceptional series of Lie groups. Here we will see how this extends to half-maximal theories by showing how a single $\mathbb{Z}_2$ generalised orbifold (or O-fold) of ExFT gives rise to M-theory on an interval, type II with orientifold planes and the heterotic theories in an elegant fashion. We study in more detail such orbifold and orientifold actions preserving half-maximal supersymmetry, and show how the half-maximal structure of ExFT permits the inclusion of localised non-Abelian vector multiplets located at the orbifold fixed points. This allows us to reproduce for the $\mathbb{Z}_2$ example the expected modifications to the gauge transformations, Bianchi identities and actions of the theories obtained from the single ExFT starting point. We comment on the prospects of studying anomaly cancellation and more complicated, non-perturbative O-folds in the ExFT framework., Comment: 89 pages (54 pages + appendix) more...
- Published
- 2018
- Full Text
- View/download PDF
31. Locally non-geometric fluxes and missing momenta in M-theory
- Author
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Lust, Dieter, Malek, Emanuel, and Syvari, Marc
- Subjects
High Energy Physics - Theory ,General Relativity and Quantum Cosmology - Abstract
We use exceptional field theory to describe locally non-geometric spaces of M-theory of more than three dimensions. For these spaces, we find a new set of locally non-geometric fluxes which lie in the R-R sector in the weak-coupling limit and can typically be characterised by mixed symmetry tensors. These spaces thus provide new examples of non-geometric backgrounds which go beyond the NS-NS sector of string theory. Starting from twisted tori we construct duality chains that lead to these new non-geometric backgrounds and we show that, just as in the four-dimensional case, there are missing momenta associated to the mixed symmetry tensors., Comment: 49 pages; v2: Published version, minor changes made more...
- Published
- 2017
- Full Text
- View/download PDF
32. Ten-dimensional origin of Minkowski vacua in ${\cal N}=8$ supergravity
- Author
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Malek, Emanuel and Samtleben, Henning
- Subjects
High Energy Physics - Theory ,General Relativity and Quantum Cosmology - Abstract
Maximal supergravity in four dimensions admits two inequivalent dyonic gaugings of the group $\mathrm{SO}(4) \times \mathrm{SO}(2,2) \ltimes T^{16}$. Both admit a Minkowski vacuum with residual $\mathrm{SO}(4) \times \mathrm{SO}(2)^2$ symmetry and identical spectrum. We explore these vacua and their deformations. Using exceptional field theory, we show that the four-dimensional theories arise as consistent truncations from IIA and IIB supergravity, respectively, around a $\mathrm{Mink}_4\times S^3\times H^3$ geometry. The IIA/IIB truncations are efficiently related by an outer automorphism of $\mathrm{SL}(4) \subset \mathrm{E}_{7(7)}$. As an application, we give an explicit uplift of the moduli of the vacua into a 4-parameter family of ten-dimensional solutions. more...
- Published
- 2017
- Full Text
- View/download PDF
33. Universal Walker metrics
- Author
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Hervik, Sigbjørn and Málek, Tomáš
- Subjects
General Relativity and Quantum Cosmology ,High Energy Physics - Theory - Abstract
We consider four dimensional spaces of neutral signature and give examples of universal spaces of Walker type. These spaces have no analogue in other signatures in four dimensions and provide with a new class of spaces being universal., Comment: 22 pages, matches published version more...
- Published
- 2017
- Full Text
- View/download PDF
34. Half-maximal consistent truncations using exceptional field theory
- Author
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Malek, Emanuel
- Subjects
High Energy Physics - Theory - Abstract
We show how to construct half-maximal consistent truncations of 10- and 11-dimensional supergravity to seven dimensions using exceptional field theory. This procedure gives rise to a seven-dimensional half-maximal gauged supergravity coupled to $n$ vector multiplets, with $n \neq 3$ in general. We also show how these techniques can be used to reduce exceptional field theory to heterotic double field theory., Comment: Proceedings prepared for the "Workshop on Geometry and Physics", November 2016, Ringberg Castle, Germany more...
- Published
- 2017
35. Half-maximal supersymmetry from exceptional field theory
- Author
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Malek, Emanuel
- Subjects
High Energy Physics - Theory ,General Relativity and Quantum Cosmology - Abstract
We study $D \geq 4$-dimensional half-maximal flux backgrounds using exceptional field theory. We define the relevant generalised structures and also find the integrability conditions which give warped half-maximal $\mathrm{Minkowski}_D$ and $\mathrm{AdS}_D$ vacua. We then show how to obtain consistent truncations of type II / 11-dimensional SUGRA which break half the supersymmetry. Such truncations can be defined on backgrounds admitting exceptional generalised $\mathrm{SO}(d-1-N)$ structures, where $d = 11 - D$, and $N$ is the number of vector multiplets obtained in the lower-dimensional theory. Our procedure yields the most general embedding tensors satisfying the linear constraint of half-maximal gauged SUGRA. We use this to prove that all $D\geq 4$ half-maximal warped $\mathrm{AdS}_D$ and Minkowski$_D$ vacua of type II / 11-dimensional SUGRA admit a consistent truncation keeping only the gravitational supermultiplet. We also show to obtain heterotic double field theory from exceptional field theory and comment on the M-theory / heterotic duality. In five dimensions, we find a new $\mathrm{SO}(5,N)$ double field theory with a $(6+N)$-dimensional extended space. Its section condition has one solution corresponding to 10-dimensional ${\cal N}=1$ supergravity and another yielding six-dimensional ${\cal N}=\left(2,0\right)$ SUGRA., Comment: 105 pages; v2: Added a section proving consistency of truncation at the level of the equations of motion, and some references; v3: Published version, minor typos corrected more...
- Published
- 2017
- Full Text
- View/download PDF
36. Non-geometric Kaluza-Klein monopoles and magnetic duals of M-theory R-flux backgrounds
- Author
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Lust, Dieter, Malek, Emanuel, and Szabo, Richard J.
- Subjects
High Energy Physics - Theory ,Mathematical Physics - Abstract
We introduce a magnetic analogue of the seven-dimensional nonassociative octonionic R-flux algebra that describes the phase space of M2-branes in four-dimensional locally non-geometric M-theory backgrounds. We show that these two algebras are related by a Spin(7) automorphism of the 3-algebra that provides a covariant description of the eight-dimensional M-theory phase space. We argue that this algebra also underlies the phase space of electrons probing a smeared magnetic monopole in quantum gravity by showing that upon appropriate contractions, the algebra reduces to the noncommutative algebra of a spin foam model of three-dimensional quantum gravity, or to the nonassociative algebra of electrons in a background of uniform magnetic charge. We realise this set-up in M-theory as M-waves probing a delocalised Kaluza-Klein monopole, and show that this system also has a seven-dimensional phase space. We suggest that the smeared Kaluza-Klein monopole is non-geometric because it cannot be described by a local metric. This is the magnetic analogue of the local non-geometry of the R-flux background and arises because the smeared Kaluza-Klein monopole is described by a U(1)-gerbe rather than a U(1)-fibration., Comment: 19 pages, 2 figures; v2: dimensionful factors corrected throughout, exposition improved; Final version to be published in JHEP more...
- Published
- 2017
- Full Text
- View/download PDF
37. From Exceptional Field Theory to Heterotic Double Field Theory via K3
- Author
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Malek, Emanuel
- Subjects
High Energy Physics - Theory ,General Relativity and Quantum Cosmology - Abstract
In this paper we show how to obtain the heterotic double field theory from exceptional field theory by breaking half of the supersymmetry. We focus on the $\mathrm{SL}(5)$ exceptional field theory and show that when the extended space contains a generalised $\mathrm{SU}(2)$-structure manifold one can define a reduction to obtain the heterotic $\mathrm{SO}(3,n)$ double field theory. In this picture, the reduction on the $\mathrm{SU}(2)$-structure breaks half of the supersymmetry of the exceptional field theory and the gauge group of the heterotic double field theory is given by the embedding tensor of the reduction used. Finally, we study the example of a consistent truncation of M-theory on K3 and recover the duality with the heterotic string on $T^3$. This suggests that the extended space can be made sense of even in the case of non-toroidal compactifications., Comment: 23 pages; v2: minor changes, published version more...
- Published
- 2016
- Full Text
- View/download PDF
38. 7-dimensional ${\cal N}=2$ Consistent Truncations using $\mathrm{SL}(5)$ Exceptional Field Theory
- Author
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Malek, Emanuel
- Subjects
High Energy Physics - Theory ,General Relativity and Quantum Cosmology - Abstract
We show how to construct seven-dimensional half-maximally supersymmetric consistent truncations of 11-/10-dimensional SUGRA using $\mathrm{SL}(5)$ exceptional field theory. Such truncations are defined on generalised $\mathrm{SU}(2)$-structure manifolds and give rise to seven-dimensional half-maximal gauged supergravities coupled to $n$ vector multiplets and thus with scalar coset space $\mathbb{R}^+ \times \mathrm{O}(3,n)/\mathrm{O}(3)\times\mathrm{O}(n)$. The consistency conditions for the truncation can be written in terms of the generalised Lie derivative and take a simple geometric form. We show that after imposing certain "doublet" and "closure" conditions, the embedding tensor of the gauged supergravity is given by the intrinsic torsion of generalised $\mathrm{SU}(2)$-connections and automatically satisfies the linear constraint of seven-dimensional half-maximal gauged supergravities, as well as the quadratic constraint when the section condition is satisfied., Comment: 46 pages; v2: minor changes, published version more...
- Published
- 2016
- Full Text
- View/download PDF
39. Non-associativity in non-geometric string and M-theory backgrounds, the algebra of octonions, and missing momentum modes
- Author
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Gunaydin, Murat, Lust, Dieter, and Malek, Emanuel
- Subjects
High Energy Physics - Theory ,General Relativity and Quantum Cosmology - Abstract
We propose a non-associative phase space algebra for M-theory backgrounds with locally non-geometric fluxes based on the non-associative algebra of octonions. Our proposal is based on the observation that the non-associative algebra of the non-geometric R-flux background in string theory can be obtained by a proper contraction of the simple Malcev algebra generated by imaginary octonions. Furthermore, by studying a toy model of a four-dimensional locally non-geometric M-theory background which is dual to a twisted torus, we show that the non-geometric background is "missing" a momentum mode. The resulting seven-dimensional phase space can thus be naturally identified with the imaginary octonions. This allows us to interpret the full uncontracted algebra of imaginary octonions as the uplift of the string theory R-flux algebra to M-theory, with the contraction parameter playing the role of the string coupling constant $g_s$., Comment: 27 pages more...
- Published
- 2016
- Full Text
- View/download PDF
40. A geometric formulation of exceptional field theory
- Author
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Bosque, Pascal du, Hassler, Falk, Lust, Dieter, and Malek, Emanuel
- Subjects
High Energy Physics - Theory - Abstract
We formulate the full bosonic SL(5) exceptional field theory in a coordinate-invariant manner. Thereby we interpret the 10-dimensional extended space as a manifold with $\mathrm{SL}(5)\times\mathbb{R}^+$-structure. We show that the algebra of generalised diffeomorphisms closes subject to a set of closure constraints which are reminiscent of the quadratic and linear constraints of maximal seven-dimensional gauged supergravities, as well as the section condition. We construct an action for the full bosonic SL(5) exceptional field theory, even when the $\mathrm{SL}(5)\times\mathbb{R}^+$-structure is not locally flat., Comment: 46 pages more...
- Published
- 2016
- Full Text
- View/download PDF
41. Dualising consistent truncations
- Author
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Malek, Emanuel
- Subjects
High Energy Physics - Theory - Abstract
We use exceptional field theory to establish a duality between certain consistent 7-dimensional truncations with maximal SUSY from IIA to IIB. We use this technique to obtain new consistent truncations of IIB on $S^3$ and $H^{p,q}$ and also give a no-go theorem for the uplift of certain gaugings., Comment: 4 pages, contribution to the proceedings of "The String Theory Universe" workshop in Leuven, 7-11 Sept 2015 more...
- Published
- 2015
- Full Text
- View/download PDF
42. An Action for F-theory: $\mathrm{SL}(2) \times \mathbb{R}^+$ Exceptional Field Theory
- Author
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Berman, David S., Blair, Chris D. A., Malek, Emanuel, and Rudolph, Felix J.
- Subjects
High Energy Physics - Theory - Abstract
We construct the 12-dimensional exceptional field theory associated to the group $\mathrm{SL}(2) \times \mathbb{R}^+$ . Demanding the closure of the algebra of local symmetries leads to a constraint, known as the section condition, that must be imposed on all fields. This constraint has two inequivalent solutions, one giving rise to 11-dimensional supergravity and the other leading to F-theory. Thus $\mathrm{SL}(2) \times \mathbb{R}^+$ exceptional field theory contains both F-theory and M-theory in a single 12-dimensional formalism., Comment: 50 pages, plain Latex; v2 references updated and minor typos fixed more...
- Published
- 2015
- Full Text
- View/download PDF
43. Dualising consistent IIA / IIB truncations
- Author
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Malek, Emanuel and Samtleben, Henning
- Subjects
High Energy Physics - Theory ,General Relativity and Quantum Cosmology - Abstract
We use exceptional field theory to establish a duality between certain consistent 7-dimensional truncations with maximal SUSY from IIA to IIB. We use this technique to obtain new consistent truncations of IIB on $S^3$ and $H^{p,q}$ and work out the explicit reduction formulas in the internal sector. We also present uplifts for other gaugings of 7-d maximal SUGRA, including theories with a trombone gauging. Some of the latter can only be obtained by a non-geometric compactification., Comment: 27 pages; v2: minor typos and references corrected, published version (JHEP) more...
- Published
- 2015
- Full Text
- View/download PDF
44. The Information Metric on the moduli space of instantons with global symmetries
- Author
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Malek, Emanuel, Murugan, Jeff, and Shock, Jonathan P
- Subjects
High Energy Physics - Theory - Abstract
In this note we revisit Hitchin's prescription \cite{Hitchin} of the Fisher metric as a natural measure on the moduli space of instantons that encodes the space-time symmetries of a classical field theory. Motivated by the idea of the moduli space of supersymmetric instantons as an emergent space in the sense of the gauge/gravity duality, we extend the prescription to encode also global symmetries of the underlying theory. We exemplify our construction with the instanton solution of the $\mathbb{CP}^{N}$ sigma model on $\mathbb{R}^{2}$., Comment: 5 pages, no figures, sorry more...
- Published
- 2015
- Full Text
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45. Type II universal spacetimes
- Author
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Hervik, Sigbjørn, Málek, Tomáš, Pravda, Vojtěch, and Pravdová, Alena
- Subjects
General Relativity and Quantum Cosmology ,High Energy Physics - Theory - Abstract
We study type II universal metrics of the Lorentzian signature. These metrics simultaneously solve vacuum field equations of all theories of gravitation with the Lagrangian being a polynomial curvature invariant constructed from the metric, the Riemann tensor and its covariant derivatives of an arbitrary order. We provide examples of type II universal metrics for all composite number dimensions. On the other hand, we have no examples for prime number dimensions and we prove the non-existence of type II universal spacetimes in five dimensions. We also present type II vacuum solutions of selected classes of gravitational theories, such as Lovelock, quadratic and L(Riemann) gravities., Comment: 24 pages, matches published version in CQG more...
- Published
- 2015
- Full Text
- View/download PDF
46. Geometry and fluxes of SL(5) exceptional field theory
- Author
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Blair, Chris D. A. and Malek, Emanuel
- Subjects
High Energy Physics - Theory ,General Relativity and Quantum Cosmology - Abstract
We use a geometric approach to construct a flux formulation for the SL(5) U-duality manifest exceptional field theory. The resulting formalism is well-suited for studying gauged supergravities with geometric and non-geometric fluxes. Here we describe all such fluxes for both M-theory and IIB supergravity including the Ramond-Ramond fields for compactifications to seven dimensions. We define the locally non-geometric "R-flux" and globally non-geometric "Q-flux" for M-theory and find a new locally non-geometric R-flux for the IIB theory. We show how these non-geometric fluxes can be understood geometrically and give some examples of how they fluxes can be generated by acting with dualities on solutions with geometric or field-strength flux., Comment: 50 pages; v2: Journal version, minor typos corrected, references added more...
- Published
- 2014
- Full Text
- View/download PDF
47. Extended Kerr-Schild spacetimes: General properties and some explicit examples
- Author
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Málek, Tomáš
- Subjects
General Relativity and Quantum Cosmology ,High Energy Physics - Theory - Abstract
We study extended Kerr-Schild (xKS) spacetimes, i.e. an extension of the Kerr-Schild (KS) ansatz where, in addition to the null KS vector, a spacelike vector field appears in the metric. In contrast to the KS case, we obtain only a necessary condition under which the KS vector is geodetic. However, it is shown that this condition becomes sufficient if we appropriately restrict the geometry of the null KS and spacelike vector. It turns out that xKS spacetimes with a geodetic KS vector are of Weyl type I and the KS vector has the same optical properties in the full and background spacetimes. In the case of Kundt xKS spacetimes, the compatible Weyl types are further restricted and a few examples of such metrics are provided. The relation of pp -waves to the class of Kundt xKS spacetimes is briefly discussed. We also show that the CCLP black hole, as an example of an expanding xKS spacetime, is of Weyl type Ii, which specializes to type D in the uncharged or non-rotating limit, and that its optical matrix satisfies the optical constraint., Comment: 33 pages, revised to match the published version in CQG more...
- Published
- 2014
- Full Text
- View/download PDF
48. M-theory and Type IIB from a Duality Manifest Action
- Author
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Blair, Chris D. A., Malek, Emanuel, and Park, Jeong-Hyuck
- Subjects
High Energy Physics - Theory ,General Relativity and Quantum Cosmology - Abstract
We revisit the SL(5) U-duality manifest action constructed by Berman and Perry in an extended spacetime. Upon choosing a four-dimensional solution to the section condition constraint, the theory reduces to a four-dimensional truncation of eleven-dimensional supergravity. In this paper, we show that the theory contains more than this M-theory reduction. The section condition also admits an SL(5) inequivalent three-dimensional solution, upon which the action directly reduces to a three-dimensional truncation of type IIB supergravity. We also discuss the reduction to IIB$^*$ supergravity., Comment: 23 pages, v2: refs added, v3: published version, slight change of title more...
- Published
- 2013
- Full Text
- View/download PDF
49. An O(D,D) Invariant Hamiltonian Action for the Superstring
- Author
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Blair, Chris D. A., Malek, Emanuel, and Routh, Alasdair J.
- Subjects
High Energy Physics - Theory ,General Relativity and Quantum Cosmology - Abstract
We construct O(D,D) invariant actions for the bosonic string and RNS superstring, using Hamiltonian methods and ideas from double field theory. In this framework the doubled coordinates of double field theory appear as coordinates on phase space and T-duality becomes a canonical transformation. Requiring the algebra of constraints to close leads to the section condition, which splits the phase space coordinates into spacetime coordinates and momenta., Comment: 21 pages, v2: minor changes in section 2, refs added more...
- Published
- 2013
- Full Text
- View/download PDF
50. The O_{D,D} Geometry of String Theory
- Author
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Berman, David S., Blair, Chris D. A., Malek, Emanuel, and Perry, Malcolm J.
- Subjects
High Energy Physics - Theory - Abstract
We construct an action for double field theory using a metric connection that is compatible with both the generalised metric and the O_{D,D} structure. The connection is simultaneously torsionful and flat. Using this connection one may construct a proper covariant derivative for double field theory. We then write the doubled action in terms of the generalised torsion of this connection. This action then exactly reproduces that required for doubled field theory and gauged supergravity., Comment: 26 pages, latex, v2 typos corrected and references added more...
- Published
- 2013
- Full Text
- View/download PDF
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