Sneutrinos as two inflatons and curvaton and leptogenesis

TL;DR

This paper proposes a multi-field inflation model involving sneutrinos as inflatons and a curvaton, which aligns with current cosmological observations and can also account for the Universe's baryon asymmetry through leptogenesis.

Contribution

It introduces a novel multi-field inflation framework with sneutrinos that explains both primordial fluctuations and baryon asymmetry, consistent with recent observational constraints.

Findings

Tensor-to-scalar ratio should be larger than 10^{-4} for viability

Sneutrino decay can generate the observed baryon asymmetry

Model aligns with Planck and BICEP/Keck 2018 data

Abstract

We argue that sneutrinos can be embedded in a multi-field inflation framework where two inflatons and a curvaton simultaneously contribute to primordial fluctuations, which is consistent with current constraints on the spectral index and the tensor-to-scalar ratio from Planck and BICEP/Keck 2018. We also show that the same framework can also explain the baryon asymmetry of the Universe via leptogenesis realized by the decay of the lightest sneutrino. We investigate the parameter range for the scenario to work such as that of sneutrino masses. In particular, we show that the tensor-to-scalar ratio should be larger than $10^{-4}$ for a successful scenario.