# Instability of gravitational baryogenesis with fermions

## TL;DR

This paper demonstrates that gravitational baryogenesis models involving fermions and derivative couplings to curvature are inherently unstable, leading to the breakdown of standard cosmological evolution.

## Contribution

It generalizes previous scalar baryon results to fermions, showing the instability issue is more broadly applicable in gravitational baryogenesis.

## Key findings

- Higher order gravitational equations are strongly unstable.
- Instability destroys standard cosmology in these models.
- Results extend previous scalar baryon analysis to fermions.

## Abstract

The derivative coupling of baryonic current to the curvature scalar in gravitational baryogenesis scenarios leads to higher order equations for gravitational field. It is shown that these equations are strongly unstable and destroy standard cosmology. This is a generalization of our earlier results obtained for scalar baryons to realistic fermions.