Ponente
Descripción
Gravitational Waves (GWs) provide a remarkable perspective into the physics of the early Universe and could serve as an innovative means of investigating high-scale leptogenesis theories. In this presentation, I will examine how GW observations can can shed light on a class of GUT-inspired seesaw models based on the $U(1){B-L}$ gauge symmetry. Within these models, the scalar field $\Phi$, which is responsible for the spontaneous symmetry breaking of $U(1) {B-L}$, generates Majorana masses $M_N$ for right-handed neutrinos. Furthermore, when this scalar field has a weak coupling to the Standard Model Higgs, it naturally gives rise to an epoch of early matter domination that is closely linked to the leptogenesis scale $M_N$. This connection encodes vital information regarding various phases of flavored leptogenesis. In this context, GWs are produced by cosmic strings linked to the $U(1)_{B-L}$ gauge symmetry breaking and by the enhancement of primordial density fluctuations during the early matter-dominated epoch. I will illustrate how the characteristics and spectral features of the resultant GW background are influenced by the underlying leptogenesis scale $M_N$. A prospective detection of GWs across several frequency ranges could thus provide exclusive understanding of the origins of the matter-antimatter imbalance. Even in the absence of a detectable signal, stringent constraints could be imposed on the leptogenesis parameters that are typically unreachable through standard observational methods.
