Entropy changes in the clustering of galaxies in an expanding universe

• 作者: Mohammad Shafi Khan Naseer Iqbal Tabasum Masood
• 来源期刊: 自然科学期刊(英文)
• 学科: 数学
• 关键词: GRAVITATIONAL CLUSTERING THERMODYNAMICS ENTROPY COSMOLOGY
• 年，卷（期）: zrkxqkyw_2011,（1）
• 页码范围: 65-68
• 页数: 4页
• 分类号: O1

摘要

In the present work the approach-thermody- namics and statistical mechanics of gravitating systems is applied to study the entropy change in gravitational clustering of galaxies in an expanding universe. We derive analytically the expressions for gravitational entropy in terms of temperature T and average density n of the particles (galaxies) in the given phase space cell. It is found that during the initial stage of clustering of galaxies, the entropy decreases and finally seems to be increasing when the system attains virial equilibrium. The entropy changes are studied for different range of measuring correlation parameter b. We attempt to provide a clearer account of this phenomena. The entropy results for a system consisting of extended mass (non-point mass) particles show a similar behaviour with that of point mass particles clustering gravitationally in an expanding universe.