A note on physical mass and the thermodynamics of AdS-Kerr black holes
Number of Authors: 2
2015 (English)In: Journal of Cosmology and Astroparticle Physics, ISSN 1475-7516, E-ISSN 1475-7516, no 11, 004Article in journal (Refereed) Published
As with any black hole, asymptotically anti-de Sitter Kerr black holes are described by a small number of parameters, including a mass parameter M that reduces to the AdS-Schwarzschild mass in the limit of vanishing angular momentum. In sharp contrast to the asymptotically flat case, the horizon area of such a black hole increases with the angular momentum parameter a if one fixes M; this appears to mean that the Penrose process in this case would violate the Second Law of black hole thermodynamics. We show that the correct procedure is to fix not M but rather the physical mass E = M/(1 - a(2)/L-2)(2); this is motivated by the First Law. For then the horizon area decreases with a. We recommend that E always be used as the mass in physical processes: for example, in attempts to over-spin AdS-Kerr black holes.
Place, publisher, year, edition, pages
2015. no 11, 004
GR black holes, gravity
IdentifiersURN: urn:nbn:se:su:diva-124790DOI: 10.1088/1475-7516/2015/11/004ISI: 000365821200005OAI: oai:DiVA.org:su-124790DiVA: diva2:890781