Renormalization group improved black hole spacetimes - art. no. 043008

Citation
A. Bonanno et M. Reuter, Renormalization group improved black hole spacetimes - art. no. 043008, PHYS REV D, 6204(4), 2000, pp. 3008
Citations number
35
Language
INGLESE
art.tipo
Article
Categorie Soggetti
Physics
Journal title
PHYSICAL REVIEW D
ISSN journal
0556-2821 → ACNP
Volume
6204
Issue
4
Year of publication
2000
Database
ISI
SICI code
0556-2821(20000815)6204:4<3008:RGIBHS>2.0.ZU;2-0
Abstract
We study the quantum gravitational effects in spherically symmetric black h ole spacetimes. The effective quantum spacetime felt by a pointlike test ma ss is constructed by "renormalization group improving" the Schwarzschild me tric. The key ingredient is the running Newton constant which is obtained f rom the exact evolution equation for the effective average action. The conf ormal structure of the quantum spacetime depends on its ADM mass M and it i s similar to that of the classical Reissner-Nordstrom black hole. For M lar ger than, equal to, and smaller than a certain critical mass M-cr the space time has two, one, and no horizon(s), respectively. Its Hawking temperature , specific heat capacity, and entropy are computed as a function of M. It i s argued that the black hole evaporation stops when M approaches M-cr which is of the order of the Planck mass. In this manner a "cold" soliton-like r emnant with the near-horizon geometry of AdS(2) x S-2 is formed. As a conse quence of the quantum effects, the classical singularity at r=0 is either r emoved completely or it is at least much milder than classically; in the fi rst case the quantum spacetime has a smooth de Sitter core which would be i n accord with the cosmic censorship hypothesis even if M<M-cr.