Université de GenèveDépartement de Physique ThéoriqueCAP Genève

Gravitational wave background from non-Abelian reheating after axion-like inflation

13. May 2022
Cite as: 
P. Klose, M. Laine and S. Procacci, JCAP 05 (2022) 021 [arXiv:2201.02317].
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A pseudoscalar inflaton φ, coupled to the topological charge density of a non-Abelian sector, can decay to gauge bosons, which may thermalize rapidly. The friction felt by φ is then increased by non-Abelian "strong sphalerons", leading to a self-amplifying process that can efficiently heat up the medium. We determine a lower bound for the gravitational wave production rate from such a process, originating via hydrodynamic fluctuations and particle collisions, in terms of a minimal number of parameters. Only a moderate fraction of energy density is converted to gravitational waves, suggesting that non-Abelian models may avoid the overproduction observed in some Abelian cases.


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