We demonstrate in this work that scalar-induced gravitational waves (SIGWs) can serve as a natural and powerful probe of thermal leptogenesis occurring at extremely high scales-beyond the reach of conventional particle physics experiments. As a proof of concept, we present a simple leptogenesis model in which an early matter-dominated phase, tracking the leptogenesis scale, is responsible for...
We study stochastic gravitational waves (GW) sourced by a Higgs-like spectator field via the modulated reheating mechanism. The curvature perturbations generated by the spectator in de Sitter vacuum are blue-tilted and strongly non-Gaussian. They must be suppressed on scales probed by the CMB anisotropies but can grow large on sub-Mpc scales, generating observationally testable stochastic GWs....
