Entropy change and phase transitions in an expanding Universe. Issue 10 (10th December 2015)

• Record Type: Journal Article
• Authors: Iqbal, N.; Masood, T.; Demir, N.
• Is Part Of: Astronomische Nachrichten. Volume 336:Issue 10(2015)
• Page Start: 1025
• Page End: 1032
• Publication Date: 2015-12-10
• Subjects: galaxies: clusters: general -- galaxies: clusters: intracluster medium; Astronomy -- Periodicals; 520.5
• DOI: 10.1002/asna.201512215
• Languages: English
• ISSNs: 0004-6337

Abstract

Abstract: The work compiles a correlated study of a gravitational quasi equilibrium thermodynamic approach for establishing and signifying a unique behavior of the cosmological entropy and phase transitions in an expanding Universe. On the basis of prescribed boundary conditions for the cluster temperature a relation for the intra‐cluster medium (ICM) of galaxy clusters has been derived. A more productive and signifying approach of the correlation functions used for galaxy clustering phenomena shows a unique behavior of the entropy change where a phenomenon known as the gravitational phase transition occurs. This unique behavior occurs with a symmetry breaking from mild clustering to low clustering and from mild clustering to high clustering which differs from a normal symmetry breaking in material sciences. We also derive results for the specific latent heat associated with the phase transitions of 3.20 T c and 0.55 T c for the mildly clustered phase to the low clustered phase and from the mildly clustered phase to the highly clustered phase, respectively. (© 2015 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)