2 research outputs found
Phase-space and Black Hole Entropy of Higher Genus Horizons in Loop Quantum Gravity
In the context of loop quantum gravity, we construct the phase-space of
isolated horizons with genus greater than 0. Within the loop quantum gravity
framework, these horizons are described by genus g surfaces with N punctures
and the dimension of the corresponding phase-space is calculated including the
genus cycles as degrees of freedom. From this, the black hole entropy can be
calculated by counting the microstates which correspond to a black hole of
fixed area. We find that the leading term agrees with the A/4 law and that the
sub-leading contribution is modified by the genus cycles.Comment: 22 pages, 9 figures. References updated. Minor changes to match
version to appear in Class. Quant. Gra
A Note on the Symmetry Reduction of SU(2) on Horizons of Various Topologies
It is known that the SU(2) degrees of freedom manifest in the description of
the gravitational field in loop quantum gravity are generally reduced to U(1)
degrees of freedom on an isolated horizon. General relativity also allows
black holes with planar, toroidal, or higher genus topology for their horizons.
These solutions also meet the criteria for an isolated horizon, save for the
topological criterion, which is not crucial. We discuss the relevant
corresponding symmetry reduction for black holes of various topologies (genus 0
and ) here and discuss its ramifications to black hole entropy within
the loop quantum gravity paradigm. Quantities relevant to the horizon theory
are calculated explicitly using a generalized ansatz for the connection and
densitized triad, as well as utilizing a general metric admitting hyperbolic
sub-spaces. In all scenarios, the internal symmetry may be reduced to
combinations of U(1).Comment: 13 pages, two figures. Version 2 has several references updated and
added, as well as some minor changes to the text. Accepted for publication in
Class. Quant. Gra