General Relativity and Quantum Cosmology, abstract
gr-qc/0605113

From: Shinji Tsujikawa [view email]

Date: Sun, 21 May 2006 02:33:55 GMT (43kb)

Avoidance of future singularities in loop quantum cosmology

Authors: M. Sami, Parampreet Singh, Shinji Tsujikawa

Comments: 6 pages, 2 figures

Report-no: IGPG-06/5-4

We consider the fate of future singularities in the effective dynamics of loop quantum cosmology. Non-perturbative quantum geometric effects which lead to $\rho^2$ modification of the Friedmann equation at high energies result in generic resolution of singularities whenever energy density $\rho$ diverges at future singularities of Friedmann dynamics. Such quantum effects lead to the avoidance of a Big Rip, which is followed by a recollapsing universe stable against perturbations. Resolution of sudden singularity, the case when pressure diverges but energy density approaches a finite value depends on the ratio of the latter to a critical energy density of the order of Planck. If the value of this ratio is greater than unity, the universe escapes the sudden future singularity and becomes oscillatory.

http://arxiv.org/abs/gr-qc/0605113