Spontaneous Baryogenesis without Baryon Isocurvature

TL;DR

This paper introduces a novel class of spontaneous baryogenesis models that avoid baryon isocurvature perturbations by decoupling the baryon chemical potential from scalar field fluctuations, enabling compatibility with high-scale inflation.

Contribution

The paper presents a new mechanism for spontaneous baryogenesis that prevents baryon isocurvature, expanding the viability of such models in high-scale inflation scenarios.

Findings

Baryon isocurvature perturbations can be suppressed in spontaneous baryogenesis.

The mechanism is demonstrated with models involving non-canonical scalar fields.

Compatibility with high-scale inflation is achieved without isocurvature constraints.

Abstract

We propose a new class of spontaneous baryogenesis models that does not produce baryon isocurvature perturbations. The baryon chemical potential in these models is independent of the field value of the baryon-generating scalar, hence the scalar field fluctuations are blocked from propagating into the baryon isocurvature. We demonstrate this mechanism in simple examples where spontaneous baryogenesis is driven by a non-canonical scalar field. The suppression of the baryon isocurvature allows spontaneous baryogenesis to be compatible even with high-scale inflation.