Imprints of Dark Photons on Gravitational Wave Polarizations

TL;DR

This paper explores how dark photons can influence gravitational wave polarization through conversion processes, revealing potential imprints on the gravitational wave background in cosmological magnetic fields.

Contribution

It provides explicit formulas for the evolution of gravitational wave intensity and polarization due to dark photon interactions in cosmological magnetic fields.

Findings

Dark photons affect gravitational wave polarization states.

Formulas derived for intensity and polarization evolution.

Initial dark photon polarization imprints on gravitational wave background.

Abstract

We study conversion processes between gravitons and dark photons and reveal the effects of dark photons on the polarization of gravitational waves. Considering cosmological dark magnetic fields, we investigate the evolution of the intensity and polarization of gravitational waves through the conversion. Specifically, we demonstrate that for minimal coupling between gravitons and dark photons, the intensity, circular polarization, and linear polarization evolve separately. We derive explicit formulas for the statistical mean and variance of the intensity and polarization when the gravitational waves pass through magnetic fields with random orientation. The formulas capture how the initial polarization of dark photons will be imprinted on the observed gravitational wave background.