Entropy changes in the clustering of galaxies in an expanding universe

Abstract

In the present work the approach-thermodynamics 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.

Fundamental Cause of Bio-Chirality: Space-Time Symmetry—Concept Review

“…The fundamental significance of biochirality at the molecular and cellular levels assumes the mechanisms of the organism/brain morphology, behavior, cognition, and consciousness are grounded on basic principles of spatial organization and function. The biochirality concept is closely associated with all vital events of the organism, including fertilization, asymmetric cell division, organism development (bi-laterality), biological information processing (brain functional asymmetry), and ageing [166][167][168][175][176][177][178][179][180]. The study of the mechanism of human consciousness and cognitive functions traditionally concern the sensory perception of space-time geometry [181][182][183][184][185].…”

Particles Spontaneous Concentrating

“…It led us to the conclusion that the entropy in isolated system goes spontaneously decrease in our consulted restricted case. Naseer Iqbal concluded a similar result in his study in the field of gravitational universe [2]. Many others studies the entropy of the universe [3].…”

Testing an Entropy Estimator Related to the Dynamical State of Galaxy Clusters

“…As any thermodynamic system, selfgravitating systems progress in the sense of increasing entropy (Lifshitz & Pitaevskii 1981;Tremaine, Hénon & Lynden-Bell 1986;Pontzen & Governato 2013) towards the state of dynamical equilibrium described above. Galaxy clustering simulations also confirm this fact (Saslaw & Hamilton 1984;Iqbal et al 2006Iqbal et al , 2011. Due to the scattering experienced by galaxies in the phase-space of clusters, these become the regions within the LSS where first-order entropy production occurs by increasing the randomness of the motion of galaxies during their gravitational accumulation.…”