Inhomogeneous baryogenesis, cosmic antimatter, and dark matter

TL;DR

This paper proposes a model of inhomogeneous baryogenesis that predicts the formation of baryonic and antibaryonic compact objects, potentially explaining dark matter as baryonic or antimatter in the universe.

Contribution

It introduces a coupling mechanism between the scalar baryon field and inflaton, leading to formation of diverse baryonic structures and antimatter objects, expanding baryogenesis models.

Findings

High baryon number objects can significantly contribute to cosmological mass density.

The entire dark matter could be baryonic according to the model.

Existence of primordial antimatter objects like anti-stars is possible.

Abstract

A model of inhomogeneous baryogenesis based on the Affleck and Dine mechanism is described. A simple coupling of the scalar baryon field to the inflaton allows for formation of astronomically significant bubbles with a large baryon (or antibaryon) asymmetry. During the farther evolution these domains form compact stellar-like objects, or lower density clouds, or primordial black holes of different size. According to the scenario, such high baryonic number objects occupy relatively small fraction of space but despite that they may significantly contribute to the cosmological mass density. For some values of parameters the model allows the possibility the whole dark matter in the universe to be baryonic. Furthermore, the model allows the existence of the antibaryonic B-bubbles, i.e. a significant fraction of the mass density in the universe can be in the form of the compact antimatter objects (e.g. anti-stars).