1998/12/09 by Juan Maldacena, Jeremy Michelson, Andrew Strominger · 1 citation
Physics and Astronomy · #hep-th
paper · pdf · doi:10.1088/1126-6708/1999/02/011
published as JHEP 9902:011,1999 · harvmac (uses epsf), 27 pages with 6 eps figures
arxiv created 1998/12/09 · arxiv updated 2009/11/30
Low-energy, near-horizon scaling limits of black holes which lead to string theory on AdS2 x S2 are described. Unlike the higher-dimensional cases, in the simplest approach all finite-energy excitations of AdS2 x S2 are suppressed. Surviving zero-energy configurations are described. These can include tree-like structures in which the AdS2 x S2 throat branches as the horizon is approached, as well as disconnected AdS2 x S2 universes. In principle, the black hole entropy counts the quantum ground states on the moduli space of such configurations. In a nonsupersymmetric context AdSD for general D can be unstable against instanton-mediated fragmentation into disconnected universes. Several examples are given.