Results 11  20
of
99
Bulk Dynamics in Confining Gauge Theories
, 2007
"... We consider gauge/string duality (in the supergravity approximation) for confining gauge theories. The system under scrutiny is a 5dimensional consistent truncation of type IIB supergravity obtained using the PapadopoulosTseytlin ansatz with boundary momentum added. We develop a gaugeinvariant an ..."
Abstract

Cited by 13 (0 self)
 Add to MetaCart
We consider gauge/string duality (in the supergravity approximation) for confining gauge theories. The system under scrutiny is a 5dimensional consistent truncation of type IIB supergravity obtained using the PapadopoulosTseytlin ansatz with boundary momentum added. We develop a gaugeinvariant and sigmamodelcovariant approach to the dynamics of 5dimensional bulk fluctuations. For the MaldacenaNunez subsystem, we study glueball mass spectra. For the KlebanovStrassler subsystem, we compute the linearized equations of motion for the 7scalar system, and show that a 3scalar sector containing the scalar dual to the gluino bilinear decouples in the UV. We solve the fluctuation equations exactly in the ”moderate UV ” approximation and check this approximation numerically. Our results demonstrate the feasibility of analyzing the generally coupled equations for scalar bulk fluctuations, and constitute a step on the way towards computing correlators Gauge/string duality offers an alternative approach to aspects of supersymmetric non
New stability results for Einstein scalar gravity
, 2010
"... We consider asymptotically anti de Sitter gravity coupled to a scalar field with mass slightly above the BreitenlohnerFreedman bound. This theory admits a large class of consistent boundary conditions characterized by an arbitrary function W. An important open question is to determine which W admit ..."
Abstract

Cited by 13 (2 self)
 Add to MetaCart
(Show Context)
We consider asymptotically anti de Sitter gravity coupled to a scalar field with mass slightly above the BreitenlohnerFreedman bound. This theory admits a large class of consistent boundary conditions characterized by an arbitrary function W. An important open question is to determine which W admit stable ground states. It has previously been shown that the total energy is bounded from below if W is bounded from below and the bulk scalar potential V (φ) admits a suitable superpotential. We extend this result and show that the energy remains bounded even in some cases where W can become arbitrarily negative. As one application, this leads to the possibility that in gauge/gravity duality, one can add a double trace operator with negative coefficient to the dual field theory and still have a stable vacuum. ar X iv
Dilatonic repulsons and confinement via the AdS/CFT correspondence,” Phys
 Rev. D
"... Abstract: We study a class of dilatonic deformations of asymptotically AdS5 ×S 5 geometry analytically and numerically. The spacetime is nonsupersymmetric and suffers from a naked singularity. We propose that the causality bound may serve as a criterion for such a geometry with a naked singularity ..."
Abstract

Cited by 11 (4 self)
 Add to MetaCart
(Show Context)
Abstract: We study a class of dilatonic deformations of asymptotically AdS5 ×S 5 geometry analytically and numerically. The spacetime is nonsupersymmetric and suffers from a naked singularity. We propose that the causality bound may serve as a criterion for such a geometry with a naked singularity to still make sense in the AdS/CFT correspondence. We show that the static string, the one corresponding to a large Wilson loop in the dual gauge theory, reveals confinement in a certain range of parameters of our solutions, where the singularity exhibits the repulsion that can well cloak the singularity from the static string probe. In particular, we find the exact expression for the tension of the QCD strings. We also discuss a
Holographic order parameter for charge fractionalization,” arXiv:1205.5291 [hepth
"... Nonlocal order parameters for deconfinement, such as the entanglement entropy and Wilson loops, depend on spatial surfaces Σ. These observables are given holographically by the area of a certain bulk spatial surface Γ ending on Σ. At finite charge density it is natural to consider the electric flux ..."
Abstract

Cited by 7 (1 self)
 Add to MetaCart
(Show Context)
Nonlocal order parameters for deconfinement, such as the entanglement entropy and Wilson loops, depend on spatial surfaces Σ. These observables are given holographically by the area of a certain bulk spatial surface Γ ending on Σ. At finite charge density it is natural to consider the electric flux through the bulk surface Γ in addition to its area. We show that this flux provides a refined order parameter that can distinguish ‘fractionalized ’ phases, with charged horizons, from what we term ‘cohesive ’ phases, with charged matter in the bulk. Fractionalization leads to a volume law for the flux through the surface, the flux for deconfined but cohesive phases is between a boundary and a volume law, while finite density confined phases have vanishing flux through the surface. We suggest two possible field theoretical interpretations for this order parameter. The first is as information extracted from the large N reduced density matrix associated to Σ. The second is as surface operators dual to polarized bulk ‘Dbranes’, carrying an electric dipole moment. ar
Holographic Correlators for General Gauge Mediation
"... We use holographic techniques to compute twopoint functions of operators belonging to a conserved current supermultiplet in theories which break supersymmetry at strong coupling. These are the relevant quantities one has to compute in models of gauge mediation to determine the soft spectrum in sup ..."
Abstract

Cited by 7 (2 self)
 Add to MetaCart
(Show Context)
We use holographic techniques to compute twopoint functions of operators belonging to a conserved current supermultiplet in theories which break supersymmetry at strong coupling. These are the relevant quantities one has to compute in models of gauge mediation to determine the soft spectrum in supersymmetric extensions of the Standard Model (SSM). Such holographic approach can be used for diverse gravitational backgrounds, but here we focus, for definiteness, on asymptotically AdS backgrounds. After presenting the general framework, we apply our formulas to two explicit examples which differ by the nature of the SSM gauginos, which have Dirac or Majorana masses, corresponding to models that respectively preserve or break Rsymmetry. ar X iv
On massless 4D Gravitons from Asymptotically AdS5 Spacetimes
, 2006
"... Preprint typeset in JHEP style HYPER VERSION ..."
(Show Context)
Hyperscaling violation : a unified frame for effective holographic theories
 JHEP 1211 (2012) 061, [arXiv:1210.0540
"... We investigate systematic classifications of low energy and lower dimensional effective holographic theories with Lifshitz and Schrödinger scaling symmetries only using metrics in terms of hyperscaling violation (θ) and dynamical (z) exponents. Their consistent parameter spaces are constrained by ..."
Abstract

Cited by 5 (2 self)
 Add to MetaCart
(Show Context)
We investigate systematic classifications of low energy and lower dimensional effective holographic theories with Lifshitz and Schrödinger scaling symmetries only using metrics in terms of hyperscaling violation (θ) and dynamical (z) exponents. Their consistent parameter spaces are constrained by null energy and positive specific heat conditions, whose validity is explicitly checked against a previously known result. From dimensional reductions of many microscopic string solutions, we observe the classifications are tied with the number of scales in the original microscopic theories. Conformal theories do not generate a nontrivial θ for a simple sphere reduction. Theories with Lifshitz scaling with one scale are completely fixed by θ and z, and have a universal emblackening factor at finite temperature. Dimensional reduction of intersecting M2M5 requires, we call, spatial anisotropic exponents (]), along with z = 1, θ = 0, because of another scale. Theories with Schrödinger scaling show similar simple classifications at zero temperature, while require more care due to an additional parameter being a thermodynamic variable at finite temperature. ar X iv
Fake supergravity and domain wall stability
 Rev. D71
, 2006
"... We review the generalized WittenNester spinor stability argument for flat domain wall solutions of gravitational theories. Neither the field theory nor the solution need be supersymmetric. Nor is the spacetime dimension restricted. We develop the nontrivial extension required for AdSsliced domai ..."
Abstract

Cited by 2 (0 self)
 Add to MetaCart
(Show Context)
We review the generalized WittenNester spinor stability argument for flat domain wall solutions of gravitational theories. Neither the field theory nor the solution need be supersymmetric. Nor is the spacetime dimension restricted. We develop the nontrivial extension required for AdSsliced domain walls and apply this to show that the recently proposed “Janus ” solution of Type IIB supergravity is stable nonperturbatively for a broad class of deformations. Generalizations of this solution to arbitrary dimension and a simple curious linear dilaton solution of Type IIB supergravity are byproducts of this work. 1 1
The Enhançon Mechanism in String Theory
, 2002
"... The enhançon mechanism is a specific phenomenon in string theory which resolves a certain naked spacetime singularity arising in the supergravity description related to N = 2 supersymmetric pure gauge theory. After reviewing the problem of singularities in general relativity as well as in string the ..."
Abstract

Cited by 2 (0 self)
 Add to MetaCart
The enhançon mechanism is a specific phenomenon in string theory which resolves a certain naked spacetime singularity arising in the supergravity description related to N = 2 supersymmetric pure gauge theory. After reviewing the problem of singularities in general relativity as well as in string theory, and discussing the prototypical enhançon example constructed by wrapping D6–branes on a K3 surface, the thesis presents three generalisations to this static spherically symmetric case pertaining to large N SU(N) gauge theory. First we will use orientifolds to show how the enhançon mechanism also works in similar situations related to SO(2N +1), USp(2N) and SO(2N) gauge theories. Second we will wrap D–brane distributions on K3 to obtain the enhançon in oblate, toroidal and prolate shapes. Third we will study a rotating enhançon configuration and consider its implications for the black hole entropy and the second law of thermodynamics.
Holographic Aspects of a Relativistic Nonconformal Theory,” Adv.High Energy Phys
 2013 (2013) 389541 [arXiv:1209.0842 [hepth
"... We study a general Ddimensional Schwarzschildtype black brane solution of the Einsteindilaton theory and derive, by using the holographic renormalization, its thermodynamics consistent with the geometric results. Using the membrane paradigm, we calculate the several hydrodynamic transport coeffi ..."
Abstract

Cited by 2 (1 self)
 Add to MetaCart
(Show Context)
We study a general Ddimensional Schwarzschildtype black brane solution of the Einsteindilaton theory and derive, by using the holographic renormalization, its thermodynamics consistent with the geometric results. Using the membrane paradigm, we calculate the several hydrodynamic transport coefficients and compare them with the results obtained by the Kubo formula, which shows the selfconsistency of the gauge/gravity duality in the relativistic nonconformal theory. In order to understand more about the relativistic nonconformal theory, we further investigate the binding energy, drag force, and holographic entanglement entropy of the relativistic nonconformal theory.