Cosmic Birefringence

Isotropic

Methods

• Minami et al. 2019: describes a method to simutaneously determine birefringence and detector miscalibration using galactic foreground emission, assuming the galactic foreground has zero EB correlation.
• Sherwin and Namikawa 2021: miscalibration free measurements of isotropic birefringence using reionization bump.
• Namikawa 2021: use CMB mode coupling to constrain isotropic birefringence.
• Lee, Hotinli, and Kamionkowski 2022: use polarized SZ effect to probe cosmic birefringence.
• Diego-Palazuelos, Mart\’ınez-González, et al. 2022: validate method of (Minami et al. 2019) with realistic simulations of Planck HFI. Conclude that the method is robust to miscalibration error but suffer from foreground EB.
• Jost, Errard, and Stompor 2022: proposes a generalized parametric foreground separation approach based on CMB polarization that accounts for cosmic birefringence. Claims that 0.35\(^{\circ}\) detection can be ruled out at 5\(\sigma\) by near future CMB experiment using this approach, assuming an in-lab calibration priors.

Measurements

• Minami and Komatsu 2020: performs a search based on method described in (Minami et al. 2019), finding \(\beta=0.35\pm 0.14^{\circ}\).
• Diego-Palazuelos, Eskilt, et al. 2022: repeat (Minami and Komatsu 2020) with Planck PR4 data, finding \(\beta=0.30\pm 0.11^{\circ}\).
• Ferguson et al. 2022: measure time-dependent rotation with SPT-3G data.
• Eskilt and Komatsu 2022: measure isotropic birefringence using Planck and WMAP, arriving at \(\beta=0.342 \pm 0.09^{\circ}\) which has a statistical significance of 3.6\(\sigma\).

Anistropic

Measurements

• Namikawa et al. 2020: constrain anistropic birefringence using quadratic estimator with ACT DR4 data, finding an upper limit of \(A_{\rm CB}=10^{-5}\).
• Bianchini et al. 2020: constrain with SPTpol data, finding consistent upperlimit as (Namikawa et al. 2020).

Systematics

• Planck on dust polarization: Planck 353GHz data shows a EE/BB ratio of about 2, with a positive TE and a weaker, parity violating, TB have been detected, while dust EB remains compatible with 0.
• Clark et al. 2021: investigate origin of EB correlation in Galactic foreground, suggesting its a result of misalignment between filamentary structure and magnetic field.
• Cukierman, Clark, and Halal 2022: provides observational evidence for misalignment between filaments and magnetic field by comparing Planck polarized dust emission and HI measurement from HI4PI. They find a \(\sim 2^{\circ}\) global misalignment which is roughly scale independent.
• Vacher et al. 2022: extending Clark et al. 2021 and Cukierman, Clark, and Halal 2022. Developed an analytic framework and worked out the frequency dependence of dust spectrum such as EE, BB, and EB.
• Monelli et al. 2022: study non-idealities of half-wave plate as a source of cosmic birefringence systematics.

Physics

• Nakatsuka, Namikawa, and Komatsu 2022: calculate EB power spectrum from axion model, following similar idea as (Sherwin and Namikawa 2021) which uses the difference between recombination and reionization. Focused on isotropic birefringence.
• Greco, Bartolo, and Gruppuso 2022: extends Nakatsuka, Namikawa, and Komatsu 2022 to anistropic birefringence.
• Kitajima et al. 2022: explains birefringence through domain walls of axion-like particles
• Jain et al. 2022: calculates the expected isotropic and anisotropic birefringence from a network of cosmic string and domain walls formed by axion-like particles. They constrained such effect using existing anistropic measurements. They also found that the isotropic birefringence detected and the non-detection of anistropic birefringence signal is incompatible within this model.

Tools

• Cai and Guan 2021: modified class to calculate rotated power spectrum using non-perturbative calculation. It supports both isotropic and anisotropic birefringences.

References