Black hole versus cosmological horizon entropy

Tamara M. Davis, Paul Davies, Charles H. Lineweaver

Research output: Contribution to journalArticle

40 Citations (Scopus)

Abstract

The generalized second law of thermodynamics states that entropy always increases when all event horizons are attributed with an entropy proportional to their area. We test the generalized second law by investigating the change in entropy when dust, radiation and black holes cross a cosmological event horizon. We generalize for flat, open and closed Friedmann-Robertson-Walker universes by using numerical calculations to determine the cosmological horizon evolution. In most cases, the loss of entropy from within the cosmological horizon is more than balanced by an increase in cosmological event horizon entropy, maintaining the validity of the generalized second law of thermodynamics. However, an intriguing set of open universe models shows an apparent entropy decrease when black holes disappear over the cosmological event horizon. We anticipate that this apparent violation of the generalized second law will disappear when solutions are available for black holes embedded in arbitrary backgrounds.

Original languageEnglish (US)
Pages (from-to)2753-2764
Number of pages12
JournalClassical and Quantum Gravity
Volume20
Issue number13
DOIs
StatePublished - Jul 7 2003
Externally publishedYes

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horizon
event horizon
entropy
universe
thermodynamics
dust
radiation

ASJC Scopus subject areas

  • Physics and Astronomy(all)

Cite this

Black hole versus cosmological horizon entropy. / Davis, Tamara M.; Davies, Paul; Lineweaver, Charles H.

In: Classical and Quantum Gravity, Vol. 20, No. 13, 07.07.2003, p. 2753-2764.

Research output: Contribution to journalArticle

Davis, Tamara M. ; Davies, Paul ; Lineweaver, Charles H. / Black hole versus cosmological horizon entropy. In: Classical and Quantum Gravity. 2003 ; Vol. 20, No. 13. pp. 2753-2764.
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