# Particle Production via Dirac Dipole Moments in the Magnetized and Non-magnetized Exponentially Expanding Universe

## TL;DR

This paper investigates Dirac particle production and polarization in 2+1D exponentially expanding universes with and without magnetic fields, analyzing how dipole moments influence charge distribution and conductivity over cosmic time.

## Contribution

It provides a detailed analysis of Dirac equation solutions, polarization, and dipole moments in expanding universes, highlighting the effects of magnetic fields on particle production and universe charge dynamics.

## Key findings

- Magnetic fields affect Dirac particle polarization and magnetization densities.
- Dipole moments influence charge distribution and conductivity in the universe.
- Asymptotic behaviors of solutions inform particle production mechanisms.

## Abstract

In the present paper, we solve the Dirac equation in the 2+1 dimensional exponentially expanding magnetized by uniform magnetic field and non-magnetized universes, separately. Asymptotic behaviors of the solutions are determined. Using these results we discuss the current of a Dirac particle to discuss the polarization densities and the magnetization density in the context of Gordon decomposition method. In this work we also calculate the total polarization and magnetization, to investigate that the magnetic field how can effect on the particle production. Furthermore, the electric and the magnetic dipole moments calculated, and based on these we have discussed the effects of the dipole moments on the charge distribution of the universe and its conductivity for both the early and the future time epoch in the presence/absence a constant magnetic field and exponentially expanding spacetime.