Eur. Phys. J. Plus (2015) 130: 31
https://doi.org/10.1140/epjp/i2015-15031-7

Regular Article

Bounce conditions for FRW models in modified gravity theories

DST-Centre for Interdisciplinary Mathematical Sciences, Faculty of Science, Banaras Hindu University, 221005, Varanasi, India

^* e-mail: yahoo_raghav@rediffmail.com

Received: 31 July 2014
Revised: 20 November 2014
Accepted: 21 November 2014
Published online: 25 February 2015

Abstract

In this paper, we have derived the minimal conditions for a bounce to occur in FRW cosmologies for the theories like Hoyle-Narlikar creation field theory, Lyra geometry, Brans-Dicke theory, general class of Scalar-Tensor theories, Einstein’s theory with variable cosmological term, with bulk viscosity and Finslerian cosmology. We derive the model-independent minimal necessary conditions for non-singular bounce and show that there is an open temporal region surrounding the bounce over which the strong energy condition (SEC) must be violated. Null energy condition is also violated in some of the modified gravity theories.