From: Spudboy100@aol.com
Date: Thu May 08 2003 - 23:08:43 MDT
A analysis of why entropy might "appear" to reverse in an open universe.
http://xxx.lanl.gov/list/astro-ph/new
astro-ph/0305121
Title: Black hole versus cosmological horizon entropy
Authors: Tamara M. Davis (1), P. C. W. Davies (2), Charles H. Lineweaver
University of New South Wales, (2) Macquarie University, Australia)
Comments: 14 pages, including 6 figures, to appear in Classical and
Quantum Gravity
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 show 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.
Or will it?
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