Detectable Gravitational Wave Signals from Affleck-Dine Baryogenesis

Abstract

In Affleck-Dine baryogenesis, the observed baryon asymmetry of the Universe is generated through the evolution of the vacuum expectation value of a scalar condensate. This scalar condensate generically fragments into nontopological solitons ( balls). If they are sufficiently long-lived, they lead to an early matter domination epoch, which enhances the primordial gravitational wave signal for modes that enter the horizon during this epoch. The sudden decay of the balls results in a rapid transition from matter to radiation domination, producing a sharp peak in the gravitational wave power spectrum. Avoiding the gravitino over-abundance problem favors scenarios where the peak frequency of the resonance is within the range of the Einstein telescope and/or DECIGO. This observable signal provides a mechanism to test Affleck-Dine baryogenesis.