AdS Brane Research Articles

End of the world brane meets TT¯\\documentclass[12pt]{minimal} \\usepackage{amsmath} \\usepackage{wasysym} \\usepackage{amsfonts} \\usepackage{amssymb} \\usepackage{amsbsy} \\usepackage{mathrsfs} \\usepackage{upgreek} \\setlength{\\oddsidemargin}{-69pt} \\begin{document}$$ T\\overline{T} $$\\end{document}

End of the world branes in AdS have been recently used to study problems deeply connected to quantum gravity, such as black hole evaporation and holographic cosmology. With non-critical tension and Neumann boundary condition, the end of the world brane often represents part of the degrees of freedom in AdS gravity and geometrically it is only part of the entire boundary. On the other hand, holographic TT¯\\documentclass[12pt]{minimal} \\usepackage{amsmath} \\usepackage{wasysym} \\usepackage{amsfonts} \\usepackage{amssymb} \\usepackage{amsbsy} \\usepackage{mathrsfs} \\usepackage{upgreek} \\setlength{\\oddsidemargin}{-69pt} \\begin{document}$$ T\\overline{T} $$\\end{document} deformation can also give a boundary as a cutoff surface for AdS gravity. In this paper we consider AdS gravity with both the end of the world boundary and the cutoff boundary. Using partial reduction we obtain a brane world gravity glued to a TT¯\\documentclass[12pt]{minimal} \\usepackage{amsmath} \\usepackage{wasysym} \\usepackage{amsfonts} \\usepackage{amssymb} \\usepackage{amsbsy} \\usepackage{mathrsfs} \\usepackage{upgreek} \\setlength{\\oddsidemargin}{-69pt} \\begin{document}$$ T\\overline{T} $$\\end{document} deformed bath. We compute both entanglement entropy and Page curve, and find agreement between the holographic results and island formula results.

(2,0) theory on S5 × S1 and quantum M2 branes

The superconformal index Z of the 6d (2,0) theory on S5×S1 (which is related to the localization partition function of 5d SYM on S5) should be captured at large N by the quantum M2 brane theory in the dual M-theory background. Generalizing the type IIA string theory limit of this relation discussed in arXiv:2111.15493 and arXiv:2304.12340, we consider semiclassically quantized M2 branes in a half-supersymmetric 11d background which is a twisted product of thermal AdS7 and S4. We show that the leading non-perturbative term at large N is reproduced precisely by the 1-loop partition function of an “instanton” M2 brane wrapped on S1×S2 with S2⊂S4. Similarly, the (2,0) theory analog of the BPS Wilson loop expectation value is reproduced by the partition function of a “defect” M2 brane wrapped on thermal AdS⊂3 AdS7. We comment on a curious analogy of these results with similar computations in arXiv:2303.15207 and arXiv:2307.14112 of the partition function of quantum M2 branes in AdS×4S7/Zk which reproduced the corresponding localization expressions in the ABJM 3d gauge theory.

Aspects of dynamical cobordism in AdS/CFT

The cobordism conjecture implies that consistent theories of Quantum Gravity must admit the introduction of boundaries. We study the dynamical realization of the cobordism conjecture in type IIB in AdS5 × S5, using the existing gravity duals of 4d \U0001d4a9 = 4 SYM with Gaiotto-Witten superconformal boundary conditions (near-horizon limits of D3-branes ending on NS5- and D5-branes). We show that these configurations are, from the 5d perspective, dynamical cobordism solutions which start from an asymptotic AdS5 vacuum and evolve until they hit an end of the world (ETW) brane with AdS4 worldvolume. The latter displays localization of gravity, and provide a completion of the Karch-Randall (KR) AdS branes, in which the backreaction of running scalars replace the KR cusp in the warp factor with a smooth bump. The dynamical scalars are either in the SO(6) invariant AdS5 bulk sector (e.g. describing the S5 size and its shrinking at the cobordism boundary) or brane localized (e.g. the SO(6) SO(3) × SO(3) squashing due to boundary conditions). We introduce a novel double scaling limit which zooms into the ETW brane and makes localization of gravity manifest, and which shows a tantalizing relation with wedge holography. We extend the picture to AdS5 theories with less (super)symmetry, via orbifolds and S-folds, leading to dynamical cobordisms for gravity duals of 4d theories with \U0001d4a9 = 2 and \U0001d4a9 = 3 supersymmetry.

AdS/BCFT with brane-localized scalar field

In this paper, we study the dynamics of end-of-the-world (EOW) branes in AdS with scalar fields localized on the branes as a new class of gravity duals of CFTs on manifolds with boundaries. This allows us to construct explicit solutions dual to boundary RG flows. We also obtain a variety of annulus-like or cone-like shaped EOW branes, which are not possible without the scalar field. We also present a gravity dual of a CFT on a strip with two different boundary conditions due to the scalar potential, where we find the confinement/deconfinement-like transition as a function of temperature and the scalar potential. Finally, we point out that this phase transition is closely related to the measurement-induced phase transition, via a Wick rotation.

Giant Wilson loops and AdS2/dCFT1

The 1/2-BPS Wilson loop in mathcal{N} = 4 supersymmetric Yang-Mills theory is an important and well-studied example of conformal defect. In particular, much work has been done for the correlation functions of operator insertions on the Wilson loop in the fundamental representation. In this paper, we extend such analyses to Wilson loops in the large-rank symmetric and antisymmetric representations, which correspond to probe D3 and D5 branes with AdS2× S2 and AdS2× S4 worldvolume geometries, ending at the AdS5 boundary along a one-dimensional contour. We first compute the correlation functions of protected scalar insertions from supersymmetric localization, and obtain a representation in terms of multiple integrals that are similar to the eigenvalue integrals of the random matrix, but with important differences. Using ideas from the Fermi Gas formalism and the Clustering method, we evaluate their large N limit exactly as a function of the ’t Hooft coupling. The results are given by simple integrals of polynomials that resemble the Q-functions of the Quantum Spectral Curve, with integration measures depending on the number of insertions. Next, we study the correlation functions of fluctuations on the probe D3 and D5 branes in AdS. We compute a selection of three- and four-point functions from perturbation theory on the D-branes, and show that they agree with the results of localization when restricted to supersymmetric kinematics. We also explain how the difference of the internal geometries of the D3 and D5 branes manifests itself in the localization computation.

Vacuum [formula omitted] thick brane solution with a modified Gaussian warp function

This work deals with f(R) modified gravity in five dimensional space–time. The modified Gaussian thick brane is shown to be a suitable exact solution in the framework of f(R) gravity in five dimensions, confirming with the AdS brane far from the brane. Response of the brane to gravitational fluctuations is discussed, and by working in the Einstein frame, the stability of the solution against linear perturbations is obtained, which also shows that gravitational zero mode is localized on the brane. For cosmological purposes, we consider FLRW model embedded in a proposed brane. Therefore, we arrive at two models, resembling the radiation dominated era and bouncing cosmological models.

Holographic anyonization: a systematic approach

Anyons have garnered substantial interest theoretically as well as experimentally. Due to the intricate nature of their interactions, however, even basic notions such as the equation of state for any kind of anyon gas have eluded a profound understanding so far. Using holography as a guiding principle, we propose a general method for an alternative quantization of electromagnetic degrees of freedom in the gravitational dual to obtain an effective physical description of strongly correlated anyonic systems. We then demonstrate the application of this prescription in a toy model of an anyonic fluid at finite charge density and magnetic field, dual to a dyonic black brane in AdS_4, and compute the equation of state and various transport coefficients explicitly.

Holographic entanglement entropy for massive flavours in dS 4

We examine the holographic entanglement entropy of spherical regions in de Sitter space in the presence of massive flavour fields which are modelled by probe D7 branes in AdS_5xS^5. We focus on the finite part of the massive correction to the entropy in the limits of small mass and large mass that are separated by a phase transition between two topologically distinct brane embeddings. For small masses, it approaches the flat space result for small spheres, whereas for large spheres there is a term that goes as the log of the sphere radius. For large masses, we find evidence for a universal contribution logarithmic in the mass. In all cases the entanglement entropy is smooth as the sphere radius crosses the horizon.

Brane solutions sourced by a scalar with vanishing potential and classification of scalar branes

We derive exact brane solutions of minimally coupled Einstein-Maxwell-scalar gravity in d+2 dimensions with a vanishing scalar potential. The solutions are conformal to the Lifshitz spacetime and have several properties, which make them interesting for holographic applications. In particular, the dual QFT is characterized by hyperscaling violation. We show that our solutions, together with the AdS brane and the domain wall sourced by an exponential potential, give the complete list of scalar branes sourced by a generic potential having simple (scale-covariant) scaling symmetries. This allows us to give a complete classification of both simple and interpolating brane solution of minimally coupled Einstein-Maxwell-scalar gravity, which may be very useful for holographic applications.

From the Komar Mass and Entropic Force Scenarios to the Einstein Field Equations on the Ads Brane

By bearing the Komar's definition for the mass, together with the entropic origin of gravity in mind, we find the Einstein field equations in $(n+1$)-dimensional spacetime. Then, by reflecting the ($4+1$)-dimensional Einstein equations on the ($3+1$)-hypersurface, we get the Einstein equations onto the $3$-brane. The corresponding energy conditions are also addressed. Since the higher dimensional considerations modify the Einstein field equations in the ($3+1$)-dimensions and thus the energy-momentum tensor, we get a relation for the Komar mass on the brane. In addition, the strongness of this relation compared with existing definition for the Komar mass on the brane is addressed.

Quintessence and effective AdS brane geometries

A geometric torsion dynamics leading to an effective curvature in a second-order formalism on a D4-brane is revisited with a renewed interest. We obtain two effective AdS 4 brane geometries on a vacuum created pair of [Formula: see text]-brane. One of them is shown to describe an AdS Schwarzschild spinning black hole and the other is shown to describe a spinning black hole bound state. It is argued that a D-instanton in a vacuum created anti-D3-brane within a pair may describe a quintessence. It may seem to incorporate a varying vacuum energy density in a brane universe. We consider the effective curvature scalar on S1 × S1 to analyze torsionless geometries on a vacuum created pair of [Formula: see text]-brane. The emergent AdS 3 brane is shown to describe a Schwarzschild and a Reissner–Nordstrom (RN) geometries in the presence of extra dimension(s).

Warped brane worlds in critical gravity

We investigate the brane models in arbitrary dimensional critical gravity presented in Lu and Pope (Phys Rev Lett 106:181302, 2011). For the models of the thin branes with codimension one, the Gibbons–Hawking surface term and the junction conditions are derived, with which the analytical solutions for the flat, AdS, and dS branes are obtained at the critical point of the critical gravity. It is found that all these branes are embedded in an AdS $$_{n}$$ spacetime, but, in general, the effective cosmological constant $$\varLambda $$ of the AdS $$_{n}$$ spacetime is not equal to the naked one $$\varLambda _0$$ in the critical gravity, which can be positive, zero, and negative. Another interesting result is that the brane tension can also be positive, zero, or negative, depending on the symmetry of the thin brane and the values of the parameters of the theory, which is very different from the case in general relativity. It is shown that the mass hierarchy problem can be solved in the braneworld model in the higher-derivative critical gravity. We also study the thick brane model and find analytical and numerical solutions of the flat, AdS, and dS branes. It is found that some branes will have inner structure when some parameters of the theory are larger than their critical values, which may result in resonant KK modes for some bulk matter fields. The flat branes with positive energy density and AdS branes with negative energy density are embedded in an $$n$$ -dimensional AdS spacetime, while the dS branes with positive energy density are embedded in an $$n$$ -dimensional Minkowski one.

Flavor corrections to the entanglement entropy

We consider the holographic entanglement entropy in N=4 SYM coupled to massive flavor degrees of freedom. The flavors are introduced by putting D7 branes in AdS_5. The resulting geometry including the backreaction of the branes is known in a perturbation expansion in the ratio N_f/N_c. We consider the expansion to first order, and compute the entanglement entropy of a region of the boundary. We consider two different cases for the geometry of the region: a slab and a ball. We find analytic solutions for the minimal surfaces in the bulk whose area gives the entropy, and analyze the structure of the UV divergence and the dependence on the masses. Our results confirm the general structure that was predicted by free field theory calculations, but with coefficients that depend on the coupling.

Non-linear representations of the conformal group and mapping of galileons

There are two common non-linear realizations of the 4D conformal group: in the first, the dilaton is the conformal factor of the effective metric \eta_{\mu\nu} e^{-2 \pi}; in the second it describes the fluctuations of a brane in AdS_5. The two are related by a complicated field redefinition, found by Bellucci, Ivanov and Krivonos (2002) to all orders in derivatives. We show that this field redefinition can be understood geometrically as a change of coordinates in AdS_5. In one gauge the brane is rigid at a fixed radial coordinate with a conformal factor on the AdS_5 boundary, while in the other one the brane bends in an unperturbed AdS_5. This geometrical picture illuminates some aspects of the mapping between the two representations. We show that the conformal Galileons in the two representations are mapped into each other in a quite non-trivial way: the DBI action, for example, is mapped into a complete linear combination of all the five Galileons in the other representation. We also verify the equivalence of the dilaton S-matrix in the two representations and point out that the aperture of the dilaton light-cone around non-trivial backgrounds is not the same in the two representations.

Black branes dual to striped phases

We construct inhomogeneous charged black branes in AdS, holographically dual to a phase at finite chemical potential with spontaneously broken translation invariance in one direction. These are obtained numerically, solving PDEs for the fully backreacted system. Fixing the periodicity scale, we find a second order phase transition to the inhomogeneous phase. We comment on the properties of the state emerging at low temperatures. For some models we demonstrate the existence of a branch of striped solutions but no continuous phase transition.

Falling flavors in AdS/CFT

We consider the behavior of D7 probes of supersymmetric warped geometries that are perturbed by the presence of anti-D3-branes. Such constructions are the gravitational duals of non-supersymmetric states in supersymmetric flavored gauge theories. Although the D7s that we consider do not feel a force from either D3s or anti-D3s alone, when both types of 3-branes are present the D7s deform and fall a small distance toward the 3-branes. We perform our analysis in AdS^5 x S^5 and the Klebanov-Witten solution and find qualitatively similar behavior in each case. We then extend our consideration to the approximately conical region of the Klebanov-Strassler solution and find that the effect is parametrically larger than in the AdS^5 x X^5 examples. Additionally, we discuss how these behaviors are modified by the presence of other flavors by considering the backreaction of such flavor branes in AdS^5 x X^5. Finally, we touch upon some of the implications that our results may have for model building and argue that the deformation of the worldvolume results in non-negligible corrections to soft terms in the low-energy description.

Charge expulsion from black brane horizons, and holographic quantum criticality in the plane

Quantum critical behavior in 2+1 dimensions is established via holographic methods in a 5+1-dimensional Einstein gravity theory with gauge potential form fields of rank 1 and 2. These fields are coupled to one another via a tri-linear Chern-Simons term with strength k. The quantum phase transition is physically driven by the expulsion of the electric charge from inside the black brane horizon to the outside, where it gets carried by the gauge fields which acquire charge thanks to the Chern-Simons interaction. At a critical value k=k_c, zero temperature, and any finite value of the magnetic field, the IR behavior is governed by a near-horizon Lifshitz geometry. The associated dynamical scaling exponent depends on the magnetic field. For k<k_c, the flow towards low temperature is governed by a Reissner-Nordstrom-like black brane whose charge and entropy density are non-vanishing at zero temperature. For k > k_c, the IR flow is towards the purely magnetic brane in AdS_6. Its near-horizon geometry is AdS_4 \times R^2, so that the entropy density vanishes quadratically with temperature, and all charge is carried by the gauge fields outside of the horizon.

A double coset ansatz for integrability in AdS/CFT

We give a proof that the expected counting of strings attached to giant graviton branes in AdS_5 x S^5, as constrained by the Gauss Law, matches the dimension spanned by the expected dual operators in the gauge theory. The counting of string-brane configurations is formulated as a graph counting problem, which can be expressed as the number of points on a double coset involving permutation groups. Fourier transformation on the double coset suggests an ansatz for the diagonalization of the one-loop dilatation operator in this sector of strings attached to giant graviton branes. The ansatz agrees with and extends recent results which have found the dynamics of open string excitations of giants to be given by harmonic oscillators. We prove that it provides the conjectured diagonalization leading to harmonic oscillators.

Wilsonian renormalisation and the exact cut-off scale from holographic duality

We propose a method for determining the exact correspondence between the Wilsonian cut-off scale on the boundary and its holographically dual bulk theory. We systematically construct the multi-trace Wilsonian effective action from holographic renormalisation and evolve it by integrating out the asymptotically Anti-de Sitter bulk geometry with scalar probes. The Wilsonian nature of the effective action is shown by proving that it must be either double-trace, closing in on itself under successive integrations, or have an infinite series of multi-trace terms. Focusing on composite scalar operator renormalisation, we relate the Callan-Symanzik equation, the flow of the scalar anomalous dimension and the multi-trace beta functions to their dual RG flows in the bulk. Establishing physical renormalisation conditions on the behaviour of the large-N anomalous dimension then enables us to extract the energy scales. Examples of pure AdS, GPPZ flow, black brane in AdS, M2 and M5 branes are studied before we generalise our results to arbitrary numbers of mass and thermal deformations of an ultra-violet CFT. Relations between the undeformed Wilsonian cut-off, deformation scales and the deformed Wilsonian cut-off are discussed, as is phenomenology of each considered background. We see how a mass gap, the emergent infra-red CFT scaling, etc. arise in different effective theories. We also argue that these results can have alternative interpretations through the flow of the conformal anomaly orthe Ricci scalar curvature of boundary branes. They show consistency with the c-theorem.

Black branes in AdS: BPS bounds and asymptotic charges

AbstractWe focus on black branes and toroidal black holes in N = 2 gauged supergravities that asymptote to AdS4, and derive formulas for the mass and central charge densities. We derive the corresponding BPS bound from the superalgebra of the asymptotic vacuum and illustrate our procedure with explicit examples of genuine black brane solutions with non‐trivial scalars.