New article posted - Berry phase in cyclic cosmologies

Post date: Nov 30, 2014 7:23:1 PM

Tomorrow, a new paper, in collaboration with Leonardo Banchi (UCL) on the cosmological Berry phase for cyclic universes will be posted on the arXiv. I think the abstract is self-explanatory, but I am very happy of this result. It is very theoretical and far fetched, but it is good to know that the intuition we had was not wrong.

http://arxiv.org/abs/1411.7553

Geometric phases and cyclic isotropic cosmologies

Leonardo Banchi and Francesco Caravelli

In the present paper we study the evolution of the modes of a scalar field in a cyclic cosmology. In order to keep the discussion clear, we study the features of a scalar field in a toy model, a Friedman- Robertson-Walker universe with a periodic scale factor, in which the universe expands, contracts and bounces infinite times, in the approximation in which the dynamic features of this universe are driven by some external factor, without the backreaction of the scalar field under study. In particular, we show that particle production exhibits features of the cyclic cosmology in the WKB approximation. Also, by studying the Berry phase of the scalar field, we show that contrarily to what is commonly believed, the scalar field carries information from one bounce to another in the form of a global phase which occurs to be generically non-zero.