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Title: Quantum geometry and gravitational entropy

Abstract

Most quantum states have wavefunctions that are widely spread over the accessible Hilbert space and hence do not have a good description in terms of a single classical geometry. In order to understand when geometric descriptions are possible, we exploit the AdS/CFT correspondence in the half-BPS sector of asymptotically AdS_5 x S5 universes. In this sector we devise a"coarse-grained metric operator" whose eigenstates are well described by a single spacetime topology and geometry. We show that such half-BPS universes have a non-vanishing entropy if and only if the metric is singular, and that the entropy arises from coarse-graining the geometry. Finally, we use our entropy formula to find the most entropic spacetimes with fixed asymptotic moments beyond the global charges.

Authors:
; ; ; ; ;
Publication Date:
Research Org.:
Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States)
Sponsoring Org.:
Physics Division
OSTI Identifier:
934489
Report Number(s):
LBNL-412E
TRN: US0803916
DOE Contract Number:
DE-AC02-05CH11231
Resource Type:
Journal Article
Resource Relation:
Journal Name: Journal of High Energy Physics; Journal Volume: 2007; Journal Issue: 12; Related Information: Journal Publication Date: 18 December 2007
Country of Publication:
United States
Language:
English
Subject:
72; EIGENSTATES; ENTROPY; GEOMETRY; HILBERT SPACE; METRICS; SPACE-TIME; TOPOLOGY; AdS-CFT Correspondence; Black Holes in String Theory; Gauge-gravity correspondence

Citation Formats

Simon, Joan, Balasubramanian, Vijay, Czech, Bart Iomiej, Larjo, Klaus, Marolf, Donald, and Simon, Joan. Quantum geometry and gravitational entropy. United States: N. p., 2007. Web.
Simon, Joan, Balasubramanian, Vijay, Czech, Bart Iomiej, Larjo, Klaus, Marolf, Donald, & Simon, Joan. Quantum geometry and gravitational entropy. United States.
Simon, Joan, Balasubramanian, Vijay, Czech, Bart Iomiej, Larjo, Klaus, Marolf, Donald, and Simon, Joan. Tue . "Quantum geometry and gravitational entropy". United States. doi:. https://www.osti.gov/servlets/purl/934489.
@article{osti_934489,
title = {Quantum geometry and gravitational entropy},
author = {Simon, Joan and Balasubramanian, Vijay and Czech, Bart Iomiej and Larjo, Klaus and Marolf, Donald and Simon, Joan},
abstractNote = {Most quantum states have wavefunctions that are widely spread over the accessible Hilbert space and hence do not have a good description in terms of a single classical geometry. In order to understand when geometric descriptions are possible, we exploit the AdS/CFT correspondence in the half-BPS sector of asymptotically AdS_5 x S5 universes. In this sector we devise a"coarse-grained metric operator" whose eigenstates are well described by a single spacetime topology and geometry. We show that such half-BPS universes have a non-vanishing entropy if and only if the metric is singular, and that the entropy arises from coarse-graining the geometry. Finally, we use our entropy formula to find the most entropic spacetimes with fixed asymptotic moments beyond the global charges.},
doi = {},
journal = {Journal of High Energy Physics},
number = 12,
volume = 2007,
place = {United States},
year = {Tue May 29 00:00:00 EDT 2007},
month = {Tue May 29 00:00:00 EDT 2007}
}