Evidence of isotropy at large-scale from polarizations of radio sources

TL;DR

This study confirms that radio polarization angles of active galactic nuclei are isotropic at scales larger than approximately 800 Mpc, supporting the cosmological principle of uniformity.

Contribution

It provides the first robust evidence of isotropy in radio polarization orientations at large scales, constraining models of cosmic polarization alignments.

Findings

Polarization orientations are consistent with isotropy at scales ≥ 800 Mpc.

Supports the cosmological principle of large-scale uniformity.

Constrains physical mechanisms explaining polarization alignments.

Abstract

We test the isotropy of radio polarization angle orientations with a robust and reliable dual frequency polarimetric survey of active galactic nuclei (AGN). We find that the polarization orientations are consistent with the assumption of isotropy for scales larger than or equal to $\sim 800$ Mpc. This provides further evidence of isotropy at large distance scales and is likely to impose strong constraints on some of the physical mechanisms that may be invoked to explain past observations of alignment of radio and optical polarizations at large distance scales.