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arXiv · 1107.4642

Viscous Little Rip Cosmology

I. Brevik·E. Elizalde·S. Nojiri·S. D. Odintsov
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Abstract

Dark energy of phantom or quintessence nature with an equation of state parameter $w$ almost equal to -1 often leads the universe evolution to a finite-time future singularity. An elegant solution to this problem has been recently proposed \cite{frampton11} under the form of the so-called Little Rip cosmology which appears to be a realistic alternative to the $Λ$CDM model. A viscous Little Rip cosmology is here proposed. Whereas generically bulk viscosity tends to promote the Big Rip, we find that there are a number of situations where this is not the case and where the formalism nicely adjusts itself to the Little Rip scenario. We prove, in particular, that a viscous fluid (or, equivalently, one with an inhomogeneous (imperfect) equation of state) is perfectly able to produce a Little Rip cosmology as a purely viscosity effect. The possibility of its induction as a combined result of viscosity and a general (power-like) equation of state is also investigated in detail. To finish, a physical, inertial force interpretation of the dissolution of bound structures in the Little Rip cosmology is presented.

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I. Brevik, E. Elizalde, S. Nojiri, S. D. Odintsov. 2011-10-14. Viscous Little Rip Cosmology. https://doi.org/10.1103/physrevd.84.103508

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