Matter-antimatter (a)symmetry in de Sitter Universe

TL;DR

This paper explores how matter-antimatter asymmetry in de Sitter spacetime might arise from observer-dependent effects related to causal structure and time orientation, offering a kinematic perspective complementing standard dynamical explanations.

Contribution

It introduces a novel observer-dependent framework for matter-antimatter asymmetry in de Sitter space, emphasizing causal and analytic properties over traditional dynamical mechanisms.

Findings

Matter-antimatter asymmetry may be an observer-dependent effect.

Causal structure influences matter-antimatter distribution.

Framework complements standard baryogenesis mechanisms.

Abstract

We investigate the matter-antimatter properties of elementary systems, modeled as free quantum fields, within the global structure of de Sitter spacetime. By leveraging the distinctive causal and analytic properties of de Sitter spacetime, we propose that matter-antimatter asymmetry could emerge as an observer-dependent effect shaped by time orientation within a local causal patch, rather than as a fundamental property of de Sitter Universe itself. This kinematic perspective complements, rather than replaces, standard dynamical processes (such as baryon number violation, $\texttt{CP}$ violation, and nonequilibrium processes) that fulfill Sakharov's criteria. Within this framework, the limited presence of antimatter in our predominantly matter-filled Universe, specifically within the causal patch of de Sitter spacetime under consideration, may arise from these mechanisms, though through pathways distinct from conventional interpretations.