Gravitational mechanism for baryogenesis in the cosmological QCD phase transition

TL;DR

This paper proposes a novel gravitational mechanism involving non-minimal coupling during the QCD phase transition that could explain the universe's baryon asymmetry by inducing baryon number violation and CP violation.

Contribution

It introduces a new model where gravity directly influences baryogenesis through non-minimal coupling, emphasizing gravity's central role in the process.

Findings

Gravity-induced baryon number non-conservation

CP violation during QCD phase transition

Facilitation of a first order QCD phase transition

Abstract

One of the biggest puzzles in modern cosmology is the observed baryon asymmetry in the universe. In current models of baryogenesis gravity plays a secondary role, although the process is believed to have happened in the early universe, under the influence of an intense gravitational field. In the present work we resume Sakharov's original program for baryogenesis and propose a central role for gravity in the process. This is achieved through a non-minimal coupling (NMC) between the gravitational field and both the strong interaction field and the quark fields. When in action, the present mechanism leads to baryon number non-conservation and CP violation. Moreover, the NMC induces reduced effective quark masses, which favours a first order QCD phase transition. As a consequence, a baryon asymmetry can be attained in the transition from the quark epoch to the hadron epoch.