Anisotropic multiple bounce models

Abstract

We analyze the Galileon ghost condensate implementation of a bouncing cosmological model in the presence of a non negligible anisotropic stress. We exhibit its structure, which we find to be far richer than previously thought. In particular, even restricting attention to a single set of underlying microscopic parameters, we obtain, numerically, many qualitatively different regimes: depending on the initial conditions on the scalar field leading the dynamics of the universe, the contraction phase can evolve directly towards a singularity, avoid it by bouncing once, or even bounce many times before settling into an ever-expanding phase. We clarify the behavior of the anisotropies in these various situations.

Cosmological models with asymmetric quantum bounces

“…The quantum cosmological models that arise from this approach enable the avoidance of the initial singularity, giving rise to a bounce [5,6], or even multiple bounces [7,8], which are preceded by a contraction of the scale factor and followed by an expanding phase.…”