Scalaron the mighty: producing dark matter and baryon asymmetry at reheating

TL;DR

This paper proposes a unified model where the scalaron from R^2-inflation not only drives inflation and reheating but also produces dark matter and explains baryon asymmetry through gravity-induced decays, integrating multiple cosmological phenomena.

Contribution

It introduces a complete theory combining inflation, dark matter, and baryogenesis using only gravity and scalaron, with minimal extensions to the Standard Model.

Findings

Scalaron decay can produce dark matter particles.

The model explains neutrino oscillations, inflation, and baryon asymmetry.

The theory is phenomenologically complete with minimal assumptions.

Abstract

In R^2-inflation scalaron slow roll is responsible for the inflationary stage, while its oscillations reheat the Universe. We find that the same scalaron decays induced by gravity can also provide the dark matter production and leptogenesis. With R^2-term and three Majorana fermions added to the Standard Model, we arrive at the phenomenologically complete theory capable of simultaneously explaining neutrino oscillations, inflation, reheating, dark matter and baryon asymmetry of the Universe. Besides the seesaw mechanism in neutrino sector, we use only gravity, which solves all the problems by exploiting scalaron.