Symmetry, Integrability and Geometry: Methods and Applications (SIGMA)

SIGMA 9 (2013), 013, 25 pages      arXiv:1203.5119      https://doi.org/10.3842/SIGMA.2013.013
Contribution to the Special Issue “Loop Quantum Gravity and Cosmology”

Semiclassical Loop Quantum Gravity and Black Hole Thermodynamics

Arundhati Dasgupta
University of Lethbridge, 4401 University Drive, Lethbridge T1K 7R8, Canada

Received March 22, 2012, in final form February 05, 2013; Published online February 16, 2013

Abstract
In this article we explore the origin of black hole thermodynamics using semiclassical states in loop quantum gravity. We re-examine the case of entropy using a density matrix for a coherent state and describe correlations across the horizon due to SU(2) intertwiners. We further show that Hawking radiation is a consequence of a non-Hermitian term in the evolution operator, which is necessary for entropy production or depletion at the horizon. This non-unitary evolution is also rooted in formulations of irreversible physics.

Key words: black holes; loop quantum gravity; coherent states; entanglement entropy.

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