Inflaton mass in the nuMSM inflation

TL;DR

This paper investigates reheating in a modified nuMSM model with an inflaton, finding that low reheating temperatures impose strict bounds on the inflaton mass, which is either very light or somewhat heavier than the Higgs boson.

Contribution

It provides new bounds on the inflaton mass in the nuMSM inflation model based on reheating efficiency and energy transfer constraints.

Findings

Reheating occurs at very low temperatures due to inefficient energy transfer.

Inflaton mass bounds are established: 0.1-10 GeV or 300-1000 GeV.

Reheating temperature constraints lead to specific inflaton mass ranges.

Abstract

We analyse the reheating in the modification of \nuMSM (Standard Model with three right handed neutrinos with masses below the electroweak scale) where the sterile neutrino providing the Dark Matter is generated in decays of the additional inflaton field. We deduce that due to rather inefficient transfer of energy from the inflaton to the Standard Model sector reheating tends to happen at very low temperature, thus providing strict bounds on the coupling between the inflaton and the Higgs particles. This in turn translates to the bound on the inflaton mass, which appears to be very light 0.1 GeV <~ m_I <~ 10 GeV, or slightly heavier then two Higgs masses 300 GeV <~ m_I <~ 1000 GeV.