caa a22 4500 463195779 CHVBK 20180406164922.0 cr unu---uuuuu 170326e20070901xx s 000 0 eng 10.1007/s10773-007-9340-3 doi (NATIONALLICENCE)springer-10.1007/s10773-007-9340-3 Carlip S. Department of Physics, University of California, 95616, Davis, CA, USA aut Horizons, Constraints, and Black Hole Entropy [Elektronische Daten] [S. Carlip] Black hole entropy appears to be "universal”—many independent calculations, involving models with very different microscopic degrees of freedom, all yield the same density of states. I discuss the proposal that this universality comes from the behavior of the underlying symmetries of the classical theory. To impose the condition that a black hole be present, we must partially break the classical symmetries of general relativity, and the resulting Goldstone-boson-like degrees of freedom may account for the Bekenstein-Hawking entropy. In particular, I demonstrate that the imposition of a "stretched horizon” constraint modifies the algebra of symmetries at the horizon, allowing the use of standard conformal field theory techniques to determine the asymptotic density of states. The results reproduce the Bekenstein-Hawking entropy without any need for detailed assumptions about the microscopic theory. Springer Science+Business Media, LLC, 2007 International Journal of Theoretical Physics Springer US; http://www.springer-ny.com 46/9(2007-09-01), 2192-2203 0020-7748 46:9<2192 2007 46 10773 https://doi.org/10.1007/s10773-007-9340-3 text/html Onlinezugriff via DOI 1 research-article jats NATIONALLICENCE 856 40 https://doi.org/10.1007/s10773-007-9340-3 text/html Onlinezugriff via DOI NATIONALLICENCE 100 1- Carlip S. Department of Physics, University of California, 95616, Davis, CA, USA aut NATIONALLICENCE 773 0- International Journal of Theoretical Physics Springer US; http://www.springer-ny.com 46/9(2007-09-01), 2192-2203 0020-7748 46:9<2192 2007 46 10773 Metadata rights reserved Springer special CC-BY-NC licence nationallicence BK010053 XK010053 XK010000 NATIONALLICENCE NATIONALLICENCE NL-springer