New polarimetric constraints on axion-like particles

TL;DR

This paper uses high-precision quasar polarisation measurements to place new, stringent constraints on axion-like particles, with potential for further improvements via future X-ray polarimetry observations.

Contribution

It introduces a novel method of constraining axion-like particles through quasar polarisation data, enhancing existing bounds with high-precision measurements.

Findings

Stringent limits on axion-like particles from optical polarisation data

Potential for improved constraints using upcoming X-ray polarimeters

Method applicable to objects behind galaxy clusters

Abstract

We show that the parameter space of axion-like particles can be severly constrained using high-precision measurements of quasar polarisations. Robust limits are derived from the measured bounds on optical circular polarisation and from the distribution of linear polarisations of quasars. As an outlook, this technique can be improved by the observation of objects located behind clusters of galaxies, using upcoming space-borne X-ray polarimeters.