Electroweak phase transition in the presence of hypermagnetic field and the generation of gravitational waves

Abstract

We investigate the effects of a large-scale background hypermagnetic field on the electroweak phase transition. We propose an effective weak angle which varies during the electroweak phase transition and upon its use, show that for a strong enough hypermagnetic field the phase transition occurs in two steps and becomes first-order. We obtain all of the important quantities characterizing the details of the phase transition, including the latent heat, transition temperature and duration. We then explore one of the consequences of this model which is the generation of gravitational waves. We calculate the gravitational wave energy spectrum generated during the first-order electroweak phase transition and find that, for strong enough background hypermagnetic fields, these signals can be detected by the Ultimate-DECIGO interferometer.Comment: 19 pages, 7 figures; v3: more discussions adde