Dolan, Brian P.
Compressibility of rotating black holes.
Physical Review D, 84 (12).
Interpreting the cosmological constant as a pressure, whose thermodynamically
conjugate variable is a volume, modifies the first law of black hole thermodynamics.
Properties of the resulting thermodynamic volume are investigated: the compressibility
and the speed of sound of the black hole are derived in the case of non-positive
cosmological constant. The adiabatic compressibility vanishes for a non-rotating
black hole and is maximal in the extremal case — comparable with, but still less
than, that of a cold neutron star. A speed of sound vs is associated with the adiabatic
compressibility, which is is equal to c for a non-rotating black hole and decreases as
the angular momentum is increased. An extremal black hole has v2
s = 0.9 c2 when
the cosmological constant vanishes, and more generally vs is bounded below by c/√2.
||Faculty of Science and Engineering > Mathematical Physics
Dr. Brian Dolan
||27 Jan 2012 10:10
|Journal or Publication Title:
||Physical Review D
||American Physical Society
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