Dark Matter and Baryon Asymmetry from the very Dawn of Universe

TL;DR

This paper introduces a universal inflation-era mechanism for generating dark matter and baryon asymmetry through a linear coupling of a scalar field to the inflaton, breaking quantum numbers and producing non-zero charge.

Contribution

It presents a novel inflation-based mechanism involving a linear inflaton coupling to a complex scalar field to produce dark matter and baryon asymmetry, including a specific super-heavy scalar model.

Findings

Mechanism successfully generates non-zero dark matter/baryon charge during inflation.

Linear coupling induces symmetry breaking, leading to charge asymmetry.

Model predicts observable consequences for dark matter and baryon abundance.

Abstract

We propose a universal mechanism of producing dark matter and baryon (lepton) charge at the stage of the quasi-de Sitter expansion of the Universe---inflation. The key ingredient of the mechanism is a linear coupling of the field, responsible for generation of dark matter or baryon (lepton) charge, to a function of the inflaton. During inflation this induces almost constant force dragging the corresponding field to the non-zero value. This force explicitly breaks quantum numbers associated with dark matter/baryon abundance at later stages. As a particular realization of the mechanism we introduce a super-heavy complex scalar field with the mass larger than the Hubble rate during the last e-folds of inflation. The global U(1)-symmetry is violated due to the linear coupling of the phase of the complex scalar to the inflaton. The symmetry breaking leads to the generation of a non-zero Noether charge. The latter is directly related to the dark matter abundance, or, alternatively, can be converted into baryon asymmetry, if the complex scalar carries the baryon charge.