Scale-genesis — Origin of gravitational waves

Abstract

We consider two realistic models for a scale invariant extension of the standard model, which couples with a hidden non-Abelian gauge sector. At energies around TeV, the hidden sector becomes strongly interacting, thereby generating a robust energy scale, which is transferred to the standard model sector, triggering the electroweak symmetry breaking. At a finite temperature, i.e. in the early Universe, the generation of the robust energy scale appears as a strong first-order phase transition. We calculate the gravitational wave background spectrum for both models, which is produced by the first-order phase transition. We compare the results with the experimental sensitivity of LISA and DECIGO and find the gravitational wave signal may be detected at DECIGO.