Horizon surface gravity as 2d geodesic expansion
General Relativity and Quantum Cosmology
2008-11-26 v2 High Energy Physics - Theory
Abstract
The surface gravity of any Killing horizon, in any spacetime dimension, can be interpreted as a local, two-dimensional expansion rate seen by freely falling observers when they cross the horizon. Any two-dimensional congruence of geodesics invariant under the Killing flow can be used to define this expansion, provided that the observers have unit Killing energy.
Keywords
Cite
@article{arxiv.0806.1677,
title = {Horizon surface gravity as 2d geodesic expansion},
author = {Ted Jacobson and Renaud Parentani},
journal= {arXiv preprint arXiv:0806.1677},
year = {2008}
}
Comments
7 pages; v2: 8 pages, derivation of (8) in section 3 streamlined, added new expression for the 2d expansion, minor editing