Eur. Phys. J. C (2015) 75: 200
https://doi.org/10.1140/epjc/s10052-015-3431-8

Regular Article - Theoretical Physics

Baryogenesis via Hawking-like radiation in the FRW space-time

¹ Instituto de Ciencias Nucleares, Universidad Nacional Autónoma de México, Apartado Postal 70-543, 04510, Mexico City, Distrito Federal, Mexico
² Department of Physics, California State University, Fresno, CA, 93740-8031, USA

^* e-mail: dougs@csufresno.edu

Received: 6 February 2015
Accepted: 23 April 2015
Published online: 8 May 2015

Abstract

We present a phenomenological model for baryogenesis based on particle creation in the Friedman–Robertson–Walker (FRW) space-time. This study is a continuation of our proposal that Hawking-like radiation in FRW space-time explains several physical aspects of the early Universe including inflation. In this model we study a coupling between the FRW space-time, in the form of the derivative of the Ricci scalar, and the current, , which leads to a different chemical potential between baryons and anti-baryons, resulting in an excess of baryons over anti-baryons with the right order of magnitude. In this model the generation of baryon asymmetry, in principle, occurs over the entire history of the Universe, starting from the beginning of the radiation phase. However, in practice, almost the entire contribution to the baryon asymmetry only comes from the very beginning of the Universe and is negligible thereafter. There is a free parameter in our model which can be interpreted as defining the boundary between the unknown quantum gravity regime and the inflation/baryogenesis regime covered by our model. When this parameter is adjusted to give the observed value of baryon asymmetry we get a higher than usual energy scale for our inflation model which, however, may be in line with the Grand Unified Theory scale for inflation in view of the BICEP2 and Planck results. In addition our model provides the correct temperature for the CMB photons at the time of decoupling.