2,574 research outputs found

### Microscopics of Extremal Kerr from Spinning M5 Branes

We show that the spinning magnetic one-brane in minimal five-dimensional
supergravity admits a decoupling limit that interpolates smoothly between a
self-dual null orbifold of AdS_3 \times S^2 and the near-horizon limit of the
extremal Kerr black hole times a circle. We use this interpolating solution to
understand the field theory dual to spinning M5 branes as a deformation of the
Discrete Light Cone Quantized (DLCQ) Maldacena-Stominger-Witten (MSW) CFT. In
particular, the conformal weights of the operators dual to the deformation
around AdS_3 \times S^2 are calculated. We present pieces of evidence showing
that a CFT dual to the four-dimensional extremal Kerr can be obtained from the
deformed MSW CFT.Comment: 5 page

### Introduction to the AdS/CFT correspondence

This is a pedagogical introduction to the AdS/CFT correspondence, based on
lectures delivered by the author at the third IDPASC school. Starting with the
conceptual basis of the holographic dualities, the subject is developed
emphasizing some concrete topics, which are discussed in detail. A very brief
introduction to string theory is provided, containing the minimal ingredients
to understand the origin of the AdS/CFT duality. Other topics covered are the
holographic calculation of correlation functions, quark-antiquark potentials
and transport coefficients.Comment: 64 pages, 12 figures;v2: minor improvements;v3: references adde

### New families of interpolating type IIB backgrounds

We construct new families of interpolating two-parameter solutions of type
IIB supergravity. These correspond to D3-D5 systems on non-compact
six-dimensional manifolds which are T^2 fibrations over Eguchi-Hanson and
multi-center Taub-NUT spaces, respectively. One end of the interpolation
corresponds to a solution with only D5 branes and vanishing NS three-form flux.
A topology changing transition occurs at the other end, where the internal
space becomes a direct product of the four-dimensional surface and the
two-torus and the complexified NS-RR three-form flux becomes imaginary
self-dual. Depending on the choice of the connections on the torus fibre, the
interpolating family has either N=2 or N=1 supersymmetry. In the N=2 case it
can be shown that the solutions are regular.Comment: 20 page

### Wilson Loops in N=2 Super-Yang-Mills from Matrix Model

We compute the expectation value of the circular Wilson loop in N=2
supersymmetric Yang-Mills theory with N_f=2N hypermultiplets. Our results
indicate that the string tension in the dual string theory scales as the
logarithm of the 't Hooft coupling.Comment: 37 pages, 9 figures; v2: Numerical factors corrected, simple
derivation of Wilson loop and discussion of continuation to complex lambda
added; v3: instanton partition function re-analyzed in order to take into
account a contribution of the hypermultiplet

### On the Origin of Gravity and the Laws of Newton

Starting from first principles and general assumptions Newton's law of
gravitation is shown to arise naturally and unavoidably in a theory in which
space is emergent through a holographic scenario. Gravity is explained as an
entropic force caused by changes in the information associated with the
positions of material bodies. A relativistic generalization of the presented
arguments directly leads to the Einstein equations. When space is emergent even
Newton's law of inertia needs to be explained. The equivalence principle leads
us to conclude that it is actually this law of inertia whose origin is
entropic.Comment: 29 pages, 6 figure

### Conformal Symmetry for General Black Holes

We show that the warp factor of a generic asymptotically flat black hole in
five dimensions can be adjusted such that a conformal symmetry emerges. The
construction preserves all near horizon properties of the black holes, such as
the thermodynamic potentials and the entropy. We interpret the geometry with
modified asymptotic behavior as the "bare" black hole, with the ambient flat
space removed. Our warp factor subtraction generalizes hidden conformal
symmetry and applies whether or not rotation is significant. We also find a
relation to standard AdS/CFT correspondence by embedding the black holes in six
dimensions. The asymptotic conformal symmetry guarantees a dual CFT description
of the general rotating black holes.Comment: 26 page

### Holographic duals of SQCD models in low dimensions

We obtain gravity duals to supersymmetric gauge theories in two and three
spacetime dimensions with unquenched flavor. The supergravity solutions are
generated by a set of color branes wrapping a compact cycle in a Calabi-Yau
threefold, together with another set of flavor branes extended along the
directions orthogonal to the cycle wrapped by the color branes. We construct
supergravity backgrounds which include the backreaction induced by a smeared
set of flavor branes, which act as delocalized dynamical sources of the
different supergravity fields.Comment: 42 pages, 5 figures;v2: typos correcte

### Gluon Scattering Amplitudes in Finite Temperature Gauge/Gravity Dualities

We examine the gluon scattering amplitude in N=4 super Yang-Mills at finite
temperature with nonzero R-charge densities, and in Non-Commutative gauge
theory at finite temperature. The gluon scattering amplitude is defined as a
light-like Wilson loop which lives at the horizon of the T-dual black holes of
the backgrounds we consider. We study in detail a special amplitude, which
corresponds to forward scattering of a low energy gluon off a high energy one.
For this kinematic configuration in the considered backgrounds, we find the
corresponding minimal surface which is directly related to the gluon scattering
amplitude. We find that for increasing the chemical potential or the
non-commutative parameter, the on-shell action corresponding to our Wilson loop
in the T-dual space decreases. For all of our solutions the length of the short
side of the Wilson loop is constrained by an upper bound which depends on the
temperature, the R-charge density and the non-commutative parameter. Due to
this constraint, in the limit of zeroth temperature our approach breaks down
since the upper bound goes to zero, while by keeping the temperature finite and
letting the chemical potential or the non-commutative parameter to approach to
zero the limit is smooth.Comment: 30 pages, 16 figures, minor corrections (plus improved numerical
computation for the non-commutative case

### Can the correlated stability conjecture be saved?

Correlated stability conjecture (CSC) proposed by Gubser and Mitra [1,2]
linked the thermodynamic and classical (in)stabilities of black branes. In [3]
it was shown that the thermodynamic instabilities, specifically the negative
specific heat, indeed result in the instabilities in the hydrodynamic spectrum
of holographically dual plasma excitations. Counter-examples of CSC were
presented in the context of black branes with scalar hair undergoing a
second-order phase transition [4,5]. The latter translationary invariant
horizons have scalar hair, raising the question whether the asymptotic
parameters of the scalar hair can be appropriately interpreted as additional
charges leading to a generalization of the thermodynamic stability criterion.
In this paper we show that the generalization of the thermodynamic stability
criterion of this type can not save CSC. We further present a simple
statistical model which makes it clear that thermodynamic and dynamical
(in)stabilities generically are not correlated.Comment: 9 pages, 2 figures; v2: JHEP versio

### The Holographic Dual of 2+1 Dimensional QFTs with N=1 SUSY and Massive Fundamental Flavours

The Maldacena Nastase solution is generalised to include massive fundamental
matter through the addition of a flavour profile. This gives a holographic dual
to N=1 SYM-CS with massive fundamental matter with a singularity free IR. We
study this solution in some detail confirming confinement and asymptotic
freedom. A recently proposed solution generating technique is then applied
which results in a new type-IIA supergravity solution. In a certain limit the
geometry of this solution is asymptotically AdS_4X Y, where Y is the metric at
the base of the Bryant-Salamon G_2 cone, which has topology S^3XS^3.Comment: 31 pages plus appendices, 6 figures. v3: Typos corrected, version to
appear in JHE

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