Detecting Axion-like particles using Cosmic Variance Cancellation with CMB and Radio surveys

This paper introduces a novel method to detect Axion-like particles (ALPs), potential dark matter candidates, by leveraging cosmic variance cancellation between Cosmic Microwave Background (CMB) and radio surveys. This technique exploits the frequency-dependent polarization rotation induced by ALPs, distinguishable from astrophysical foregrounds. Combining future CMB experiments with next-generation radio telescopes could significantly enhance ALP detection sensitivity, probing parameter space beyond current limits.