214 research outputs found
Emergence of CD26+ cancer stem cells with metastatic properties in colorectal carcinogenesis
published_or_final_versio
Thermodynamic Geometry and Phase Transitions in Kerr-Newman-AdS Black Holes
We investigate phase transitions and critical phenomena in Kerr-Newman-Anti
de Sitter black holes in the framework of the geometry of their equilibrium
thermodynamic state space. The scalar curvature of these state space Riemannian
geometries is computed in various ensembles. The scalar curvature diverges at
the critical point of second order phase transitions for these systems.
Remarkably, however, we show that the state space scalar curvature also carries
information about the liquid-gas like first order phase transitions and the
consequent instabilities and phase coexistence for these black holes. This is
encoded in the turning point behavior and the multi-valued branched structure
of the scalar curvature in the neighborhood of these first order phase
transitions. We re-examine this first for the conventional Van der Waals
system, as a preliminary exercise. Subsequently, we study the Kerr-Newman-AdS
black holes for a grand canonical and two "mixed" ensembles and establish novel
phase structures. The state space scalar curvature bears out our assertion for
the first order phase transitions for both the known and the new phase
structures, and closely resembles the Van der Waals system.Comment: 1 + 41 pages, LaTeX, 46 figures. Discussions, clarifications and
references adde
Logarithmic correction to BH entropy as Noether charge
We consider the role of the type-A trace anomaly in static black hole
solutions to semiclassical Einstein equation in four dimensions. Via Wald's
Noether charge formalism, we compute the contribution to the entropy coming
from the anomaly induced effective action and unveil a logarithmic correction
to the Bekenstein-Hawking area law.
The corrected entropy is given by a seemingly universal formula involving the
coefficient of the type-A trace anomaly, the Euler characteristic of the
horizon and the value at the horizon of the solution to the uniformization
problem for Q-curvature. Two instances are examined in detail: Schwarzschild
and a four-dimensional massless topological black hole. We also find agreement
with the logarithmic correction due to one-loop contribution of conformal
fields in the Schwarzschild background.Comment: 14 pages, JHEP styl
The holographic principle
There is strong evidence that the area of any surface limits the information
content of adjacent spacetime regions, at 10^(69) bits per square meter. We
review the developments that have led to the recognition of this entropy bound,
placing special emphasis on the quantum properties of black holes. The
construction of light-sheets, which associate relevant spacetime regions to any
given surface, is discussed in detail. We explain how the bound is tested and
demonstrate its validity in a wide range of examples.
A universal relation between geometry and information is thus uncovered. It
has yet to be explained. The holographic principle asserts that its origin must
lie in the number of fundamental degrees of freedom involved in a unified
description of spacetime and matter. It must be manifest in an underlying
quantum theory of gravity. We survey some successes and challenges in
implementing the holographic principle.Comment: 52 pages, 10 figures, invited review for Rev. Mod. Phys; v2:
reference adde
Logarithmic Corrections to Extremal Black Hole Entropy from Quantum Entropy Function
We evaluate the one loop determinant of matter multiplet fields of N=4
supergravity in the near horizon geometry of quarter BPS black holes, and use
it to calculate logarithmic corrections to the entropy of these black holes
using the quantum entropy function formalism. We show that even though
individual fields give non-vanishing logarithmic contribution to the entropy,
the net contribution from all the fields in the matter multiplet vanishes. Thus
logarithmic corrections to the entropy of quarter BPS black holes, if present,
must be independent of the number of matter multiplet fields in the theory.
This is consistent with the microscopic results. During our analysis we also
determine the complete spectrum of small fluctuations of matter multiplet
fields in the near horizon geometry.Comment: LaTeX file, 52 pages; v2: minor corrections, references adde
Holographic c-theorems in arbitrary dimensions
We re-examine holographic versions of the c-theorem and entanglement entropy
in the context of higher curvature gravity and the AdS/CFT correspondence. We
select the gravity theories by tuning the gravitational couplings to eliminate
non-unitary operators in the boundary theory and demonstrate that all of these
theories obey a holographic c-theorem. In cases where the dual CFT is
even-dimensional, we show that the quantity that flows is the central charge
associated with the A-type trace anomaly. Here, unlike in conventional
holographic constructions with Einstein gravity, we are able to distinguish
this quantity from other central charges or the leading coefficient in the
entropy density of a thermal bath. In general, we are also able to identify
this quantity with the coefficient of a universal contribution to the
entanglement entropy in a particular construction. Our results suggest that
these coefficients appearing in entanglement entropy play the role of central
charges in odd-dimensional CFT's. We conjecture a new c-theorem on the space of
odd-dimensional field theories, which extends Cardy's proposal for even
dimensions. Beyond holography, we were able to show that for any
even-dimensional CFT, the universal coefficient appearing the entanglement
entropy which we calculate is precisely the A-type central charge.Comment: 62 pages, 4 figures, few typo's correcte
Sepsid even-skipped enhancers are functionally conserved in Drosophila despite lack of sequence conservation
10.1371/journal.pgen.1000106PLoS Genetics46
Holographic Derivation of Kerr-Newman Scattering Amplitudes for General Charge and Spin
Near-superradiant scattering of charged scalars and fermions by a
near-extreme Kerr-Newman black hole and photons and gravitons by a near-extreme
Kerr black hole are computed as certain Fourier transforms of correlators in a
two-dimensional conformal field theory. The results agree with the classic
spacetime calculations from the 1970s, thereby providing good evidence for a
conjectured Kerr-Newman/CFT correspondence.Comment: 22 page
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