<script type="text/javascript">
<!--
document.write('<div id="oa_widget"></div>');
document.write('<script type="text/javascript" src="https://www.openaire.eu/index.php?option=com_openaire&view=widget&format=raw&projectId=undefined&type=result"></script>');
-->
</script>
handle: 11567/865760
According to statistical mechanics, micro-states of an isolated physical system (say, a gas in a box) at time $t_0$ in a given macro-state of less-than-maximal entropy typically evolve in such a way that the entropy at time $t$ increases with $|t-t_0|$ in both time directions. In order to account for the observed entropy increase in only one time direction, the thermodynamic arrow of time, one usually appeals to the hypothesis that the initial state of the universe was one of very low entropy. In certain recent models of cosmology, however, no hypothesis about the initial state of the universe is invoked. We discuss how the emergence of a thermodynamic arrow of time in such models can nevertheless be compatible with the above-mentioned consequence of statistical mechanics, appearances to the contrary notwithstanding.
14 pages LaTeX, 3 figures; v2: first paragraph added, section 8 added, 9 references added; v3: further references added
Nuclear and High Energy Physics, Cosmology and Nongalactic Astrophysics (astro-ph.CO), Statistical Mechanics (cond-mat.stat-mech), FOS: Physical sciences, Condensed Matter - Statistical Mechanics, Astrophysics - Cosmology and Nongalactic Astrophysics
Nuclear and High Energy Physics, Cosmology and Nongalactic Astrophysics (astro-ph.CO), Statistical Mechanics (cond-mat.stat-mech), FOS: Physical sciences, Condensed Matter - Statistical Mechanics, Astrophysics - Cosmology and Nongalactic Astrophysics
citations This is an alternative to the "Influence" indicator, which also reflects the overall/total impact of an article in the research community at large, based on the underlying citation network (diachronically). | 20 | |
popularity This indicator reflects the "current" impact/attention (the "hype") of an article in the research community at large, based on the underlying citation network. | Top 10% | |
influence This indicator reflects the overall/total impact of an article in the research community at large, based on the underlying citation network (diachronically). | Top 10% | |
impulse This indicator reflects the initial momentum of an article directly after its publication, based on the underlying citation network. | Average |