Axion cogenesis without isocurvature perturbations

Abstract

Axion rotations can simultaneously explain the dark matter abundance and the baryon asymmetry of the Universe by kinetic misalignment and axiogenesis. We consider a scenario in which the Peccei-Quinn symmetry breaking field is as large as the Planck scale during inflation and the axion rotation is initiated by the inflaton-induced potential immediately after the end of inflation. This is a realization of the cogenesis scenario that is free of problems with domain walls and isocurvature perturbations thanks to large explicit Peccei-Quinn symmetry breaking at the Planck scale during inflation. The baryon asymmetry can be more efficiently produced by lepto-axiogenesis, in which case the axion mass is predicted to be larger than $O(0.1)$ meV. We also discuss a UV complete model in supersymmetric theories.

12 pages, 1 figure; v2: discussions added