1999/06/30 by Iver Brevik, I. Brevik · 1 citation
Physics and Astronomy · #Black Holes and Theoretical Physics #Cosmology and Gravitation Theories #Quantum Electrodynamics and Casimir Effect #gr-qc
paper · pdf · doi:10.1103/physrevd.61.124017
published as Phys.Rev.D61:124017,2000 · 12 pages, LaTeX, no figures, minor extensions of the discussion. To appear in PRD
arxiv created 2000/03/16 · openalex publication_date 2000/05/24 · arxiv updated 2009/11/30 · openalex created_date 2025/10/10 · openalex updated_date 2026/07/28
The recent theory of 't Hooft [Nucl. Phys. B (Proc. Suppl.) 68, 174 (1998)] models the black hole as a system endowed with an envelope of matter that obeys an equation of state in the form p=(\ensuremathγ\ensuremath-1)\ensuremathρ, and acts as a source in Einstein's equations. The present paper generalizes the 't Hooft theory so as to take into account a bulk viscosity \ensuremathζ in the fluid. It is shown that even a slight positive value of \ensuremathζ will suffice to yield complete agreement with the Hawking formula for the entropy of the black hole, if the value of the constant \ensuremathγ takes a value that is slightly less than 4/3. The value \ensuremathγ=4/3 corresponds to a radiation fluid.