Forecasts on Anisotropic Cosmic Birefringence Constraints for CMB Experiment in the Northern Hemisphere

The study of cosmic birefringence through Cosmic Microwave Background (CMB) experiments is a key research area in cosmology and particle physics, providing a critical test for Lorentz and CPT symmetries. This paper focuses on an upcoming CMB experiment in the mid-latitude of the Northern Hemisphere, and investigates the potential to detect anisotropies in cosmic birefringence. Applying a quadratic estimator on simulated polarization data, we reconstruct the power spectrum of anisotropic cosmic birefringence successfully and estimate constraints on the amplitude of the spectrum, A₂₁, assuming scale invariance. The forecast is based on a wide-scan observation strategy during winter, yielding an effective sky coverage of approximately 23. 6%. We consider two noise scenarios corresponding to the short-term and long-term phases of the experiment. Our results show that with a small aperture telescope operating at 95/150GHz, the 2 upper bound for A₂₁ can reach 0. 017 under the low noise scenario when adopting the method of merging multi-frequency data in map domain, and merging multi-frequency data in spectrum domain tightens the limit by about 10%. A large-aperture telescope with the same bands is found to be more effective, tightening the 2 upper limit to 0. 0062.