295 research outputs found
Kerr-CFT From Black-Hole Thermodynamics
We analyze the near-horizon limit of a general black hole with two commuting
killing vector fields in the limit of zero temperature. We use black hole
thermodynamics methods to relate asymptotic charges of the complete spacetime
to those obtained in the near-horizon limit. We then show that some
diffeomorphisms do alter asymptotic charges of the full spacetime, even though
they are defined in the near horizon limit and, therefore, count black hole
states. We show that these conditions are essentially the same as considered in
the Kerr/CFT corresponcence. From the algebra constructed from these
diffeomorphisms, one can extract its central charge and then obtain the black
hole entropy by use of Cardy's formula.Comment: 19 pages, JHEP3, no figures. V2: References added, small typos fixe
Near Horizon of 5D Rotating Black Holes from 2D Perspective
We study the CFT dual to five dimensional extremal rotating black holes, by
investigating the two dimensional perspective of their near horizon geometry.
From two dimensional point of view, we show that both gauge fields, related to
the two rotations, appear in the same manner in the asymptotic symmetry and in
the associated central charge. We find that, our results are in perfect
agreement with the generalization of Kerr/CFT approach to five dimensional
extremal rotating black holes.Comment: The last version to appear in the European Physical Journal
Relativistic viscoelastic fluid mechanics
A detailed study is carried out for the relativistic theory of
viscoelasticity which was recently constructed on the basis of Onsager's linear
nonequilibrium thermodynamics. After rederiving the theory using a local
argument with the entropy current, we show that this theory universally reduces
to the standard relativistic Navier-Stokes fluid mechanics in the long time
limit. Since effects of elasticity are taken into account, the dynamics at
short time scales is modified from that given by the Navier-Stokes equations,
so that acausal problems intrinsic to relativistic Navier-Stokes fluids are
significantly remedied. We in particular show that the wave equations for the
propagation of disturbance around a hydrostatic equilibrium in Minkowski
spacetime become symmetric hyperbolic for some range of parameters, so that the
model is free of acausality problems. This observation suggests that the
relativistic viscoelastic model with such parameters can be regarded as a
causal completion of relativistic Navier-Stokes fluid mechanics. By adjusting
parameters to various values, this theory can treat a wide variety of materials
including elastic materials, Maxwell materials, Kelvin-Voigt materials, and (a
nonlinearly generalized version of) simplified Israel-Stewart fluids, and thus
we expect the theory to be the most universal description of single-component
relativistic continuum materials. We also show that the presence of strains and
the corresponding change in temperature are naturally unified through the
Tolman law in a generally covariant description of continuum mechanics.Comment: 52pages, 11figures; v2: minor corrections; v3: minor corrections, to
appear in Physical Review E; v4: minor change
The RN/CFT Correspondence Revisited
We reconsidered the quantum gravity description of the near horizon extremal
Reissner-Nordstr{\o}m black hole in the viewpoint of the AdS/CFT
correspondence. We found that, for pure electric case, the right moving central
charge of dual 1D CFT is which is different from the previous result of left moving sector obtained by warped AdS/CFT description. We
discussed the discrepancy in these two approaches and examined novel properties
of our result.Comment: revtex4, 16 pages, sign mistakes corrected, references include
Central Charges in Extreme Black Hole/CFT Correspondence
The Kerr/CFT correspondence has been recently broadened to the general
extremal black holes under the assumption that the central charges from the
non-gravitational fields vanish. To confirm this proposal, we derive the
expression of the conserved charges in the Einstein-Maxwell-scalar theory with
topological terms in four and five dimensions and check that the above
assumption was correct. Combining the computed central charge with the expected
form of the temperature, the Bekenstein-Hawking entropy of the general extremal
black holes in four and five dimensions can be reproduced by using the Cardy
formula.Comment: 20 pages, v2:references added, published in JHE
Kerr/CFT Correspondence in the Low Energy Limit of Heterotic String Theory
We investigate the recently proposed Kerr/CFT correspondence in the context
of heterotic string theory. The Kerr/CFT correspondence states that the
near-horizon states of an extremal four (or higher) dimensional black hole
could be identified with a certain chiral conformal field theory under the
conjecture that the central charges from the non-gravitational fields vanish.
The corresponding Virasoro algebra is generated by a class of diffeomorphisms
which preserves the appropriate boundary conditions on the near-horizon
geometry. To understand the chiral conformal field theory, we consider the
class of extremal Kerr-Sen black hole (that contains three non-gravitational
fields) as a class of solutions in the low energy limit (effective field
theory) of heterotic string theory. We derive the expression of the conserved
charges for the extremal Kerr-Sen solutions that contain dilaton, abelian gauge
filed and antisymmetric tensor filed. We confirm and extend the validity of the
conjecture (that the central charges from the non-gravitational fields vanish)
for theories including antisymmetric tensor fields. We combine the calculated
central charges with the expected form of the temperature using the Cardy
formula to obtain the entropy of the extremal black hole microscopically; in
agreement with the macroscopic Bekenstein-Hawking entropy of the extremal black
hole.Comment: 14 pages, a few sentences added to the introduction, version to
appear in JHE
Holographic Duals of Near-extremal Reissner-Nordstrom Black Holes
We consider the description of
Reissner-Nordstr{\o}m black holes by studying their uplifted counterparts in
five dimensions. Assuming a natural size of the extra dimension, the near
horizon geometries for the extremal limit are exactly . We compute the scattering amplitude of a scalar field, with a
mode near threshold of frequency and extra dimensional momentum, by a near
extremal uplifted black hole. The absorption cross section agrees with the two
point function of the CFT dual to the scalar field.Comment: reference added, improper statements corrected, 17 pages, no figure
On Non-Chiral Extension of Kerr/CFT
We discuss possible non-chiral extension of the Kerr/CFT correspondence. We
first consider the near horizon geometry of an extremal BTZ black hole and
study the asymptotic symmetry. In order to define it properly, we introduce a
regularization and show that the asymptotic symmetry becomes the desirable
non-chiral Virasoro symmetry with the same central charges for both left and
right sectors, which are independent of the regularization parameter. We then
investigate the non-chiral extension for general extremal black holes in the
zero entropy limit. Since the same geometric structure as above emerges in this
limit, we identify non-chiral Virasoro symmetry by a similar procedure. This
observation supports the existence of a hidden non-chiral CFT_2 structure with
the same central charges for both left and right sectors dual to the rotating
black holes.Comment: 29 pages, LaTeX; v2: minor corrections, references adde
Hidden Conformal Symmetry of the Reissner-Nordstr{\o}m Black Holes
Motivated by recent progresses in the holographic descriptions of the Kerr
and Reissner-Nordstr{\o}m (RN) black holes, we explore the hidden conformal
symmetry of nonextremal uplifted 5D RN black hole by studying the near horizon
wave equation of a massless scalar field propagating in this background.
Similar to the Kerr black hole case, this hidden symmetry is broken by the
periodicity of the associated angle coordinate in the background geometry, but
the results somehow testify the dual CFT description of the nonextremal RN
black holes. The duality is further supported by matching of the entropies and
absorption cross sections calculated from both CFT and gravity sides.Comment: 14 pages, no figur
On the shape of a D-brane bound state and its topology change
As is well known, coordinates of D-branes are described by NxN matrices. From
generic non-commuting matrices, it is difficult to extract physics, for
example, the shape of the distribution of positions of D-branes. To overcome
this problem, we generalize and elaborate on a simple prescription, first
introduced by Hotta, Nishimura and Tsuchiya, which determines the most
appropriate gauge to make the separation between diagonal components (D-brane
positions) and off-diagonal components. This prescription makes it possible to
extract the distribution of D-branes directly from matrices. We verify the
power of it by applying it to Monte-Carlo simulations for various lower
dimensional Yang-Mills matrix models. In particular, we detect the topology
change of the D-brane bound state for a phase transition of a matrix model; the
existence of this phase transition is expected from the gauge/gravity duality,
and the pattern of the topology change is strikingly similar to the counterpart
in the gravity side, the black hole/black string transition. We also propose a
criterion, based on the behavior of the off-diagonal components, which
determines when our prescription gives a sensible definition of D-brane
positions. We provide numerical evidence that our criterion is satisfied for
the typical distance between D-branes. For a supersymmetric model, positions of
D-branes can be defined even at a shorter distance scale. The behavior of
off-diagonal elements found in this analysis gives some support for previous
studies of D-brane bound states.Comment: 29 pages, 16 figure
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