Implications of the Cosmic Birefringence Measurement for the Axion Dark Matter Search

TL;DR

This paper links recent cosmic birefringence constraints to axion dark matter-photon coupling limits using a two-axion alignment model, connecting dark energy and dark matter in a unified framework.

Contribution

It introduces a two-axion alignment model that explains dark energy and dark matter as different linear combinations, unifying their constraints.

Findings

Relates cosmic birefringence to axion-photon coupling constraints.

Proposes a two-axion alignment mechanism for dark energy and dark matter.

Provides a unified explanation for dark sector constraints.

Abstract

We show that a recent constraint on the cosmic birefringence effect due to dark energy can be related to the constraints on the coupling of axion dark matter to photon, by relying on a simple model of two-axion alignment mechanism with periodic potentials. Owing to the alignment of the potentials, one linear combination of two fields provides a nearly flat direction and acts as dark energy, whereas the other combination provides a steep direction and acts as dark matter. This scenario solves the known conceptual issues of one-field model for dark energy and predicts the connection between seemingly disparate constraints on the dark sectors of our universe.