Brown-York quasilocal energy, gravitational charge, and black hole horizons - art. no. 064010

We study a recently proposed horizon defining identity for certain black ho le spacetimes. It relates the difference of the Brown-York quasilocal energ y and the Komar charge at the horizon to the total energy of the spacetime. The Brown-York quasilocal energy is evaluated for some specific choices of spacetime foliations. With a certain condition imposed on the matter distr ibution, we prove this identity for spherically symmetric static black hole solutions of general relativity. For these cases, we show that the identit y can be derived from a Gauss-Codacci condition that any three-dimensional time like boundary embedded around the hole must obey. We also demonstrate the validity of the identity in other cases by explicitly applying it to se veral static, non-static, asymptotically Bat, and asymptotically non-Bat bl ack hole solutions. These include the asymptotically Friedmann-Robertson-Wa lker (FRW) solutions as well as the case of a black hole with a global mono pole charge. [S0556-2821(99)05616-7].