Entropy and Gravity
The effect of gravity upon changes of the entropy of a gravity-dominated system is discussed. In a universe dominated by vacuum energy, gravity is repulsive, and there is accelerated expansion. Furthermore, inhomogeneities are inflated and the universe approaches a state of thermal equilibrium. The...
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2012-12-01
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Online Access: | http://www.mdpi.com/1099-4300/14/12/2456 |
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doaj-e57a6043c6aa480ba1f6ea4607eb5f362020-11-24T23:57:23ZengMDPI AGEntropy1099-43002012-12-0114122456247710.3390/e14122456Entropy and GravityØyvind GrønThe effect of gravity upon changes of the entropy of a gravity-dominated system is discussed. In a universe dominated by vacuum energy, gravity is repulsive, and there is accelerated expansion. Furthermore, inhomogeneities are inflated and the universe approaches a state of thermal equilibrium. The difference between the evolution of the cosmic entropy in a co-moving volume in an inflationary era with repulsive gravity and a matter-dominated era with attractive gravity is discussed. The significance of conversion of gravitational energy to thermal energy in a process with gravitational clumping, in order that the entropy of the universe shall increase, is made clear. Entropy of black holes and cosmic horizons are considered. The contribution to the gravitational entropy according to the Weyl curvature hypothesis is discussed. The entropy history of the Universe is reviewed.http://www.mdpi.com/1099-4300/14/12/2456entropygravitygravitational contractioncosmological constantblack holehorizonWeyl curvature hypothesisinflationary era |
collection |
DOAJ |
language |
English |
format |
Article |
sources |
DOAJ |
author |
Øyvind Grøn |
spellingShingle |
Øyvind Grøn Entropy and Gravity Entropy entropy gravity gravitational contraction cosmological constant black hole horizon Weyl curvature hypothesis inflationary era |
author_facet |
Øyvind Grøn |
author_sort |
Øyvind Grøn |
title |
Entropy and Gravity |
title_short |
Entropy and Gravity |
title_full |
Entropy and Gravity |
title_fullStr |
Entropy and Gravity |
title_full_unstemmed |
Entropy and Gravity |
title_sort |
entropy and gravity |
publisher |
MDPI AG |
series |
Entropy |
issn |
1099-4300 |
publishDate |
2012-12-01 |
description |
The effect of gravity upon changes of the entropy of a gravity-dominated system is discussed. In a universe dominated by vacuum energy, gravity is repulsive, and there is accelerated expansion. Furthermore, inhomogeneities are inflated and the universe approaches a state of thermal equilibrium. The difference between the evolution of the cosmic entropy in a co-moving volume in an inflationary era with repulsive gravity and a matter-dominated era with attractive gravity is discussed. The significance of conversion of gravitational energy to thermal energy in a process with gravitational clumping, in order that the entropy of the universe shall increase, is made clear. Entropy of black holes and cosmic horizons are considered. The contribution to the gravitational entropy according to the Weyl curvature hypothesis is discussed. The entropy history of the Universe is reviewed. |
topic |
entropy gravity gravitational contraction cosmological constant black hole horizon Weyl curvature hypothesis inflationary era |
url |
http://www.mdpi.com/1099-4300/14/12/2456 |
work_keys_str_mv |
AT øyvindgrøn entropyandgravity |
_version_ |
1725454234863796224 |