Cosmic no-hair theorems for viscous contracting Universes


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Authors
Ganguly, Chandrima 
Abstract

Abstract: A cosmic no-hair theorem for all initially contracting, spatially homogeneous, orthogonal Bianchi Cosmologies is derived - which shows that all such Universes asymptote to a spatially flat, isotropic Universe with the inclusion of a shear viscous stress. This establishes a new mechanism of isotropisation in a contracting Universe, which does not take recourse to an ekpyrosis-like mechanism using an effective ultra-stiff equation of state fluid, that is, one in which the pressure is much greater than the energy density.

Description
Keywords
paper, alternatives to inflation, cosmic singularity, physics of the early universe
Journal Title
Journal of Cosmology and Astroparticle Physics
Conference Name
Journal ISSN
1475-7516
Volume Title
2021
Publisher
IOP Publishing