CMB constraints on dark matter-proton scattering: investigating prior-volume effects using profile likelihoods
The study investigates how prior-volume effects bias Bayesian constraints when modeling dark matter-proton scattering using Cosmic Microwave Background (CMB) data. It found that broad priors can artificially shift results toward the Standard Model, leading to stronger constraints on the scattering cross section than frequentist methods. The paper recommends combining Bayesian and frequentist statistics for better assessment.