Arghyajit Datta (CAU), "Revisiting Matter-antimatter asymmetry in an Era of Early Matter Domination"

Wednesday 8 Apr 2026, 15:00 → 16:00 Asia/Seoul

CTPU Seminar room (Theory Bldg, 4F)

In this talk We will investigate the impact of an early matter-dominated (EMD) epoch on the generation of the matter–antimatter asymmetry. In the first part, I will show that the modified expansion rate during EMD shifts the equilibration temperatures of Standard Model interactions, including charged-lepton Yukawa processes, thereby altering the boundaries between flavor regimes in the popular leptogenesis mechanism. We then argue that this shift necessitates a re-examination of the conventional flavor-dependent leptogenesis framework, as both asymmetry production and washout are significantly affected.

In the second part, I will illustrate the effects where a late-decaying scalar condensate drives an EMD phase. In this setup, early decays can account for the observed baryon asymmetry, while late-time decays generate a large neutrino asymmetry (predicted by EMPRESS experiment) without overproducing baryons.