{"about":{"site":"https://codewithpapers.app","non_affiliation":"Code with Papers and Syntology are not affiliated with, endorsed by, or sponsored by Papers with Code, Meta, or the pwc-archive mirror.","licence":"CC BY-SA 4.0","licence_url":"https://creativecommons.org/licenses/by-sa/4.0/legalcode","attribution":"https://codewithpapers.app/attribution","modified":"archive material modified by Syntology; see the attribution page"},"url":"/paper/planck-constraints-on-cosmic-birefringence","title":"Planck constraints on Cosmic Birefringence and its cross-correlation with the CMB","arxiv_id":"2401.11973","date":"2024-01-22","proceeding":null,"authors":["G. Zagatti","M. Bortolami","A. Gruppuso","P. Natoli","L. Pagano","G. Fabbian"],"abstract":"Cosmic birefringence is the in-vacuo, frequency independent rotation of the polarization plane of linearly polarized radiation, induced by a parity-violating term in the electromagnetic Lagrangian. We implement an harmonic estimator for the birefringence field that only relies on the CMB E to B mode cross-correlation, thus suppressing the effect of cosmic variance from the temperature field. We derive constraints from Planck public releases 3 and 4, revealing a cosmic birefringence power spectrum consistent with zero at about $2\\sigma$ up to multipole $L=1500$. Moreover, we find that the cross-correlations of cosmic birefringence with the CMB T-, E- and B-fields are also well compatible with null. The latter two cross-correlations are provided here for the first time up to $L=1500$.","url_abs":"https://arxiv.org/abs/2401.11973v1","url_pdf":"https://arxiv.org/pdf/2401.11973v1.pdf","source":{"archive":"pwc-archive (Hugging Face), CC BY-SA 4.0","snapshot":"2025-07-28","licence_url":"https://creativecommons.org/licenses/by-sa/4.0/legalcode","row_kind":"links_only","authors_date_abstract":"arXiv metadata, CC0 1.0 (https://info.arxiv.org/help/license), from the Kaggle arXiv metadata snapshot of 2026-09-12"},"code_links":[{"paper_slug":"planck-constraints-on-cosmic-birefringence","repo_url":"https://github.com/giorgiazagatti/cb_planck_maps_spectra","is_official":1,"mentioned_in_paper":1,"mentioned_in_github":0,"framework":"none","reach":null},{"paper_slug":"planck-constraints-on-cosmic-birefringence","repo_url":"https://github.com/paganol/alpha_lm","is_official":1,"mentioned_in_paper":1,"mentioned_in_github":0,"framework":"none","reach":null}],"tasks":[],"methods":[],"datasets_introduced":[],"methods_introduced":[],"results":[],"syntology":{"syntology_url":null,"atlas_url":null,"mcp":null,"developers":"https://syntology.ai/developers"},"arxiv_metadata":null,"syntology_extracted_results":null}