Joint Discovery - HET seminar – University of Copenhagen

Joint Discovery - HET seminar

Speaker: Rose Lerner (University of Helsinki)

Title: Decay of the curvaton by resonant production of the higgs

Abstract: In the curvaton scenario the primordial density perturbations originate from a second scalar field, rather than the inflaton. We investigate in detail a model where the curvaton is coupled only to the Standard Model Higgs boson. In such a case, one would expect a fast non-perturbative decay of the curvaton, so that the curvaton would not have time to build up the curvature perturbation. However, we show that this is not the case, and that the curvaton decay may be delayed even down to the electroweak symmetry breaking scale. This delay is due to the thermal background generated by the inflaton decay into Standard Model degrees of freedom. Contrary to expectations, it is possible to obtain the observed curvature perturbation for large values of the higgs-curvaton coupling.