Generation of particle number asymmetry in expanding universe

TL;DR

This paper investigates how particle number asymmetry can be generated and evolves over time in an expanding universe using a nonequilibrium quantum field theory model with CP violation.

Contribution

It introduces a model with CP and particle number violation and analyzes the generation and evolution of asymmetry in an expanding universe.

Findings

Particle number asymmetry can be generated from initial conditions via interactions.

Time evolution of asymmetry is studied using perturbation methods.

The model demonstrates mechanisms for asymmetry creation in cosmological settings.

Abstract

We study creation and time evolution of particle number asymmetry with nonequilibrium quantum field theory. We introduce a model of a neutral scalar and a complex scalar and it has CP violating and particle number violating features. Starting with an initial condition specified by density operator, we show how particle number asymmetry can be generated through interaction. We investigate the time evolution of particle number asymmetry of universe using perturbation method.