Problems of spontaneous and gravitational baryogenesis

TL;DR

This paper critically analyzes spontaneous and gravitational baryogenesis, revealing that their coupling mechanisms induce higher order gravitational equations with instabilities that threaten standard cosmological models.

Contribution

It demonstrates that the coupling of curvature scalar to baryonic current causes instabilities, challenging the viability of these baryogenesis mechanisms in cosmology.

Findings

Higher order gravitational equations exhibit exponential instabilities.

Instabilities threaten the consistency of standard cosmology.

Coupling mechanisms induce nonzero baryonic asymmetry but with stability issues.

Abstract

Spontaneous and closely related to it gravitational baryogenesis are critically analyzed. It is shown that the coupling of the curvature scalar to baryonic current, which induces nonzero baryonic asymmetry of the universe, simultaneously leads to higher order gravitational equations, which have exponentially unstable solutions. It is shown that this instability endangers the standard cosmology.