Antimatter regions in the baryon-dominated Universe

TL;DR

This paper proposes a mechanism where inflation-induced quantum fluctuations create antimatter regions within a baryon-dominated universe, potentially leading to observable antimatter objects like antistar clusters without conflicting with cosmic microwave background data.

Contribution

It introduces a novel inflation-based scenario for antimatter domain formation that aligns with current cosmological observations and predicts detectable antimatter signatures.

Findings

Antimatter regions can form without disturbing CMB anisotropy.

Antistar globular clusters could exist within our galaxy.

Expected antimatter fluxes are detectable by AMS-02.

Abstract

Quantum fluctuations of a complex, baryonic charged scalar field caused by inflation can generate large domains, which convert later into antimatter regions. As a result the Universe can become globally matter-dominated, with minor contribution of antimatter regions. The distribution and evolution of such antimatter regions could cause every galaxy to be a harbour of an anti-star globular cluster. At the same time, the scenario does not lead to large-scale isocuvature perturbations, which would disturb observable CMB anisotropy. The existence of one of such antistar globular cluster in our Galaxy does not contradict the observed $\gamma$-ray background, but the expected fluxes of $\bar{\rm ^4He}$ and $\bar{\rm ^3He}$ from such an antimatter object are definitely accessible to the sensitivity of the coming AMS--02 experiment.