Analysis of perturbations in non-local cosmological models

by Dr Sergey Vernov (Skobeltsyn Institute of Nuclear Physics)

Thursday 18 Apr 2013, 11:00 → 12:00 Europe/Rome

Aula Teorici (DIFA)

It has recently been shown that ghost-free, non-local higher-derivative ultra-violet modifications of Einstein's gravity may be able to resolve the cosmological Big Bang singularity via a non-singular bounce. Within the framework of such non-local cosmological models, we derive the non-local perturbation equations for the Bardeen potentials around a large class of cosmological background solutions. We are going to study both sub- and super-Hubble perturbations around an inflationary trajectory which is preceded by the Big Bounce in the past, and demonstrate that the inflationary trajectory has an ultra-violet completion and that perturbations do not suffer from any pathologies. The talk is based on the paper by T. Biswas, A.S. Koshelev, A. Mazumdar, S.Yu. Vernov, JCAP 1208 (2012) 024, arXiv:1206.6374.