@article {Carlip:1999:0264-9381:3327,
	author = "Carlip S.",
	title = "Entropy from conformal field theory at Killing horizons",
	journal = "Classical and Quantum Gravity",
	volume = "16",
	year = "1999",
	abstract = "<P>On a manifold with a boundary, the constraint algebra of general relativity may acquire a central extension, which can be computed using covariant phase space techniques. When the boundary is a (local) Killing horizon, a natural set of boundary conditions leads to a Virasoro subalgebra with a calculable central charge. Conformal field theory methods may then be used to determine the density of states at the boundary. I consider a number of cases - black holes, Rindler space, de Sitter space, Taub-NUT and Taub-bolt spaces and dilaton gravity - and show that the resulting density of states yields the expected Bekenstein-Hawking entropy. The statistical mechanics of black hole entropy may thus be fixed by symmetry arguments, independent of the details of quantum gravity. </P>",
	pages = "3327-3348(22)",
	url = "http://www.ingentaconnect.com/content/iop/cqg/1999/00000016/00000010/art00322"
}