Two-Field ALP Dark Matter and Cosmic Birefringence
Analysis
This paper investigates the implications of cosmic birefringence, a phenomenon related to the rotation of CMB polarization, for axion-like particle (ALP) dark matter models. It moves beyond single-field models, which face observational constraints due to the 'washout effect,' by exploring a two-field ALP model. This approach aims to reconcile ALP dark matter with observations of cosmic birefringence.
Key Takeaways
- •Cosmic birefringence is used to probe beyond-standard-model cosmology.
- •ALP dark matter is a promising candidate, but single-field models face challenges.
- •Two-field ALP models can potentially overcome these challenges.
- •The superposition of two ALP fields can reconcile the model with observations.
Reference
“The superposition of two ALP fields with distinct masses can relax the constraints imposed by the washout effect and reconcile with observations.”