A curvature bound from gravitational catalysis in thermal backgrounds

Understand

We investigate the phenomenon of gravitational catalysis, i.e., curvature-induced chiral symmetry breaking and fermion mass generation, at finite temperature.

• Using a scale-dependent analysis, we derive a thermal bound on the curvature of local patches of spacetime.
• This bound quantifies regions in parameter space that remain unaffected by gravitational catalysis and thus are compatible with the existence of light fermions as observed in Nature.
• While finite temperature generically relaxes the curvature bound, we observe a comparatively strong dependence of the phenomenon on the details of the curvature.