We perform a comprehensive scan of the parameter space of a general singlet scalar
extension of the Standard Model to identify the regions which can lead to a strong first-
order phase transition, as required by the electroweak baryogenesis mechanism. We find
that taking into account bubble nucleation is a fundamental constraint on the parameter
space and present a conservative and fast...
Entropy production is a necessary ingredient for addressing the over-population of thermal relics. It is widely employed in particle physics models for explaining the origin of dark matter. A longlived particle that decays to the known particles, while dominating the universe, plays the role of the dilutor. We point out the impact of its partial decay to dark matter on the primordial matter...
We study the prospects of leptogenesis in the framework of the minimal flipped SU(5) gauge model in which the heavy Majorana neutrino mass scale is connected to the scale of unification via two-loop radiative effects. We argue that, in spite of a lower-than-usual seesaw scale, a successful thermal leptogenesis can take place in several regimes yielding a firm upper limit on the absolute light...
