2025/10/24 by Dou, Jiazheng, Zhao, Wen · 1 citation
#Cosmology and Nongalactic Astrophysics (astro-ph.CO) #FOS: Physical sciences
paper · doi:10.48550/arxiv.2510.21221
Cosmic birefringence (CB) is a promising probe of parity-violating physics beyond the Standard Model, characterized by the rotation of the linear polarization plane of cosmic microwave background (CMB) photons. This effect, quantified by the birefringence angle β, generates non-zero EB and TB correlations that are otherwise absent in standard cosmology. However, instrumental miscalibration angles α can mimic this signal, necessitating a joint estimation approach. In this work, we forecast the sensitivity of the AliCPT experiment, combined with Planck HFI data, on constraining the isotropic CB angle using a semi-analytical maximum-likelihood method. We simulate observations under various foreground complexities, rotation angles, and scanning strategies, and demonstrate that AliCPT can achieve an uncertainty of σ(β)=0.09^∘ with one-year data, which will improve to 0.026^∘ after four years' observations. We also find that neglecting or mismodeling the foreground EB correlation will introduce significant biases, which can be alleviated under a clean but small sky patch.