Abstract
The first law of black hole mechanics was derived by Wald in a general covariant theory of gravity for stationary variations around a stationary black hole. It is formulated in terms of Noether charges and has many advantages. In this paper several issues are discussed to strengthen the validity of the Noether charge form of the first law. In particular, a gauge condition used in the derivation is justified. After that, we justify the generalization to nonstationary variations done by Iyer and Wald.
- Received 17 September 1998
DOI:https://doi.org/10.1103/PhysRevD.59.064009
©1999 American Physical Society