17,870 research outputs found
Diffeomorphism on Horizon as an Asymptotic Isometry of Schwarzschild Black Hole
It is argued that the diffeomorphism on the horizontal sphere can be regarded
as a nontrivial asymptotic isometry of the Schwarzschild black hole. We propose
a new boundary condition of asymptotic metrics near the horizon and show that
the condition admits the local time-shift and diffeomorphism on the horizon as
the asymptotic symmetry.Comment: 18 pages, no figures, corrected some typo
Asymptotic tails of massive scalar fields in a stationary axisymmetric EMDA black hole geometry
The late-time tail behavior of massive scalar fields is studied analytically
in a stationary axisymmetric EMDA black hole geometry. It is shown that the
asymptotic behavior of massive perturbations is dominated by the oscillatory
inverse power-law decaying tail at the intermediate
late times, and by the asymptotic tail at asymptotically
late times. Our result seems to suggest that the intermediate tails and the asymptotically tails
may be quite general features for evolution of massive scalar fields in any
four dimensional asymptotically flat rotating black hole backgrounds.Comment: 6 page
Quantum entropy of the Kerr black hole arising from gravitational perturbation
The quantum entropy of the Kerr black hole arising from gravitational
perturbation is investigated by using Null tetrad and \'t Hooft\'s brick-wall
model. It is shown that effect of the graviton\'s spins on the subleading
correction is dependent of the square of the spins and the angular momentum per
unit mass of the black hole, and contribution of the logarithmic term to the
entropy will be positive, zero, and negative for different value of .Comment: 8 pages, 1 figure, Latex. to appear in Phys. Rev.
Statistical Entropy of a Stationary Dilaton Black Hole from Cardy Formula
With Carlip's boundary conditions, a standard Virasoro subalgebra with
corresponding central charge for stationary dilaton black hole obtained in the
low-energy effective field theory describing string is constructed at a Killing
horizon. The statistical entropy of stationary dilaton black hole yielded by
standard Cardy formula agree with its Bekenstein-Hawking entropy only if we
take period of function as the periodicity of the Euclidean black
hole. On the other hand, if we consider first-order quantum correction then the
entropy contains a logarithmic term with a factor , which is different
from Kaul and Majumdar's one, . We also show that the discrepancy is
not just for the dilaton black hole, but for any one whose corresponding
central change takes the form .Comment: 11 pages, no figure, RevTex. Accepted for publication in Phys. Rev.
Entropies of Rotating Charged Black Holes from Conformal Field Theory at Killing Horizons
The covariant phase technique is used to compute the constraint algebra of
the stationary axisymmetric charged black hole. A standard Virasoro subalgebra
with corresponding central charge is constructed at a Killing horizon with
Carlip's boundary conditions. For the Kerr-Newman black hole and the
Kerr-Newman-AdS black hole, the density of states determined by conformal
fields theory methods yields the statistical entropy which agrees with the
Bekenstein-Hawking entropy.Comment: 12 pages, no figure, RevTe
The Power Spectrum, Bias Evolution, and the Spatial Three-Point Correlation Function
We calculate perturbatively the normalized spatial skewness, , and full
three-point correlation function (3PCF), , induced by gravitational
instability of Gaussian primordial fluctuations for a biased tracer-mass
distribution in flat and open cold-dark-matter (CDM) models. We take into
account the dependence on the shape and evolution of the CDM power spectrum,
and allow the bias to be nonlinear and/or evolving in time, using an extension
of Fry's (1996) bias-evolution model. We derive a scale-dependent,
leading-order correction to the standard perturbative expression for in
the case of nonlinear biasing, as defined for the unsmoothed galaxy and
dark-matter fields, and find that this correction becomes large when probing
positive effective power-spectrum indices. This term implies that the inferred
nonlinear-bias parameter, as usually defined in terms of the smoothed density
fields, might depend on the chosen smoothing scale. In general, we find that
the dependence of on the biasing scheme can substantially outweigh that
on the adopted cosmology. We demonstrate that the normalized 3PCF, , is an
ill-behaved quantity, and instead investigate , the variance-normalized
3PCF. The configuration dependence of shows similarly strong
sensitivities to the bias scheme as , but also exhibits significant
dependence on the form of the CDM power spectrum. Though the degeneracy of
with respect to the cosmological parameters and constant linear- and
nonlinear-bias parameters can be broken by the full configuration dependence of
, neither statistic can distinguish well between evolving and non-evolving
bias scenarios. We show that this can be resolved, in principle, by considering
the redshift dependence of .Comment: 41 pages, including 12 Figures. To appear in The Astrophysical
Journal, Vol. 521, #
Transformations of q-boson and q-fermion algebras
We investigate the algebras satisfied by q-deformed boson and fermion
oscillators, in particular the transformations of the algebra from one form to
another. Based on a specific algebra proposed in recent literature, we show
that the algebra of deformed fermions can be transformed to that of undeformed
standard fermions. Furthermore we also show that the algebra of q-deformed
fermions can be transformed to that of undeformed standard bosons.Comment: 7 pages, RevTe
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