# Baryogenesis via Gravitational Spontaneous Symmetry Breaking

## TL;DR

This paper proposes a new gravitational mechanism for baryogenesis involving a scalar charged under U(1)_{B-L} coupling to curvature invariants, which can generate matter-antimatter asymmetry during inflation and reheating.

## Contribution

It introduces a novel baryogenesis mechanism via gravitational spontaneous symmetry breaking through Gauss-Bonnet couplings during inflation.

## Key findings

- The mechanism can produce the observed matter-antimatter asymmetry.
- Analytic and numerical analyses confirm the viability of the proposed process.

## Abstract

We study baryogenesis in effective field theories where a $\mathrm{U}(1)_{ B-L}$-charged scalar couples to gravity via curvature invariants. We analyze the general possibilities in such models, noting the relationships between some of them and existing models, such as Affleck-Dine baryogenesis. We then identify a novel mechanism in which $\mathrm{U}(1)_{ B-L}$ can be broken by couplings to the Gauss-Bonnet invariant during inflation and reheating. Using analytic methods, we demonstrate that this mechanism provides a new way to dynamically generate the net matter-anti-matter asymmetry observed today, and verify this numerically.