# Polarized backgrounds of relic gravitons

## TL;DR

This paper introduces a new gauge-invariant framework for analyzing the polarization states of relic gravitons in cosmological backgrounds, drawing an analogy with optical Jones calculus to classify polarization interactions.

## Contribution

It presents a novel bispinor-based approach to describe graviton polarizations, providing a compact classification of polarization interactions in cosmological settings.

## Key findings

- Framework establishes a gauge-invariant description of tensor mode polarizations.
- Analogy with Jones calculus offers a new perspective on graviton polarization interactions.
- Classification scheme for polarization effects in relic gravitons.

## Abstract

The polarizations of the tensor modes of the geometry evolving in cosmological backgrounds are treated as the components of a bispinor whose dynamics follows from an appropriate gauge-invariant action. This novel framework bears a close analogy with the (optical) Jones calculus and leads to a compact classification of the various interactions able to polarize the relic gravitons.