The search for cosmic polarization rotation or birefringence in the cosmic microwave background (CMB) is well motivated because it can provide powerful constraints on parity-violating new physics, such as axion-like particles. In this paper, we point out that since the CMB polarization is produced at two very different redshifts – it is generated at both reionization and recombination – new parity-violating physics can generically rotate the polarization signals from these different sources by different amounts. We explore two implications of this. First, measurements of CMB birefringence are challenging because the effect is degenerate with a miscalibration of CMB polarization angles; however, by taking the difference of the reionization and recombination birefringence angles (measured from different CMB angular scales), we can obtain a cosmological signal that is immune to instrumental angle miscalibration. Secondly, we note that the combination with other methods for probing birefringence can give tomographic information, constraining the redshift origin of any physics producing birefringence. We forecast that the difference of the reionization and recombination birefringence angles can be competitively determined to within ∼0.05 deg for future CMB satellites such as LiteBIRD. Although much further work is needed, we argue that foreground mitigation for this measurement should be less challenging than for inflationary B-mode searches on similar scales due to larger signals and lower foregrounds.
Sherwin, Blake D. and Namikawa, Toshiya. "Cosmic birefringence tomography and calibration independence with reionization signals in the CMB." Monthly Notices of the Royal Astronomical Society, vol. 520, no. 3, Feb. 2023. https://doi.org/10.1093/mnras/stac3146
Sherwin, Blake D., & Namikawa, Toshiya (2023). Cosmic birefringence tomography and calibration independence with reionization signals in the CMB. Monthly Notices of the Royal Astronomical Society, 520(3). https://doi.org/10.1093/mnras/stac3146
Sherwin, Blake D., and Namikawa, Toshiya, "Cosmic birefringence tomography and calibration independence with reionization signals in the CMB," Monthly Notices of the Royal Astronomical Society 520, no. 3 (2023), https://doi.org/10.1093/mnras/stac3146
@article{osti_2422911,
author = {Sherwin, Blake D. and Namikawa, Toshiya},
title = {Cosmic birefringence tomography and calibration independence with reionization signals in the CMB},
annote = {ABSTRACT The search for cosmic polarization rotation or birefringence in the cosmic microwave background (CMB) is well motivated because it can provide powerful constraints on parity-violating new physics, such as axion-like particles. In this paper, we point out that since the CMB polarization is produced at two very different redshifts – it is generated at both reionization and recombination – new parity-violating physics can generically rotate the polarization signals from these different sources by different amounts. We explore two implications of this. First, measurements of CMB birefringence are challenging because the effect is degenerate with a miscalibration of CMB polarization angles; however, by taking the difference of the reionization and recombination birefringence angles (measured from different CMB angular scales), we can obtain a cosmological signal that is immune to instrumental angle miscalibration. Secondly, we note that the combination with other methods for probing birefringence can give tomographic information, constraining the redshift origin of any physics producing birefringence. We forecast that the difference of the reionization and recombination birefringence angles can be competitively determined to within ∼0.05 deg for future CMB satellites such as LiteBIRD. Although much further work is needed, we argue that foreground mitigation for this measurement should be less challenging than for inflationary B-mode searches on similar scales due to larger signals and lower foregrounds.},
doi = {10.1093/mnras/stac3146},
url = {https://www.osti.gov/biblio/2422911},
journal = {Monthly Notices of the Royal Astronomical Society},
issn = {ISSN 0035-8711},
number = {3},
volume = {520},
place = {United States},
publisher = {Oxford University Press},
year = {2023},
month = {02}}
Lawrence Berkeley National Laboratory (LBNL), Berkeley, CA (United States). National Energy Research Scientific Computing
Center (NERSC)
Sponsoring Organization:
USDOE
Grant/Contract Number:
AC02-05CH11231
OSTI ID:
2422911
Journal Information:
Monthly Notices of the Royal Astronomical Society, Journal Name: Monthly Notices of the Royal Astronomical Society Journal Issue: 3 Vol. 520; ISSN 0035-8711