Quasar polarization with two axionlike particles

TL;DR

This paper explores a model with two axion-like particles, a scalar and a pseudoscalar, which together can explain quasar polarization observations by canceling circular polarization effects while maintaining linear polarization.

Contribution

It introduces a two-ALP model that accounts for quasar polarization data, resolving previous inconsistencies with single ALP scenarios.

Findings

Scalar and pseudoscalar effects cancel circular polarization.

Linear polarization remains consistent with observations.

Model aligns with polarization data across optical and radio wavelengths.

Abstract

Recently, it was shown, that the absence of circular polarization of visible light from quasars, severely constrains the interpretation of axion like particles (ALPs) as a solution for the generation of the linear polarization. Furthermore, the new observation of the linear polarization in the radio wavelength from quasars, similar to the earlier observation performed in the optical band, makes the ALPs scenario inconsistent with at least one of the two observations. In this study we extend this scenario, to two axion like particles, one scalar and another pseudoscalar. We find, that the effects from scalar and pseudoscalar cancel out each other, thereby suppressing the circular polarization, while preserving consistent linear polarization, as observed in both visible and radio waves bands.