Friday, March 22, 2013

1303.5167 (Arturo Avelino et al.)

Bulk Viscous Matter-dominated Universes: Asymptotic Properties    [PDF]

Arturo Avelino, Ricardo Garcia-Salcedo, Tame Gonzalez, Ulises Nucamendi, Israel Quiros
By means of a combined study of the type Ia supernovae test,together with a study of the asymptotic properties in the equivalent phase space -- through the use of the dynamical systems tools -- we demonstrate that the bulk viscous matter-dominated scenario is not a good model to explain the accepted cosmological paradigm, at least, under the parametrization of bulk viscosity considered in this paper. The main objection against such scenarios is the absence of conventional radiation and matter-dominated critical points in the phase space of the model. This entails that radiation and matter dominance are not generic solutions of the cosmological equations, so that these stages can be implemented only by means of very particular solutions. Such a behavior is in marked contradiction with the accepted cosmological paradigm which requires of an earlier stage dominated by relativistic species, followed by a period of conventional non-relativistic matter domination, during which the cosmic structure we see was formed.
View original: http://arxiv.org/abs/1303.5167

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