# Gravitational Wave -- Gauge Field Dynamics

## TL;DR

This paper explores how gravitational waves interact with cosmic gauge fields, revealing they gain effective mass, become birefringent, and oscillate with gauge field excitations, offering new insights into gravitational physics.

## Contribution

It introduces the concept of gravitational wave -- gauge field oscillations and shows how gauge fields alter gravitational wave properties in a cosmological context.

## Key findings

- Gravitational waves acquire an effective mass in gauge fields.
- Gravitational waves become birefringent when propagating through gauge fields.
- Normal modes are mixtures of gravitational and gauge field excitations.

## Abstract

The dynamics of a gravitational wave propagating through a cosmic gauge field are dramatically different than in vacuum. We show that a gravitational wave acquires an effective mass, is birefringent, and its normal modes are a linear combination of gravitational waves and gauge field excitations, leading to the phenomenon of gravitational wave -- gauge field oscillations. These surprising results provide insight into gravitational phenomena and may suggest new approaches to a theory of quantum gravity.