Can primordial parity violation explain the observed cosmic birefringence?

Tomohiro Fujita, Yuto Minami, Maresuke Shiraishi, Shuichiro Yokoyama

Research output: Contribution to journalArticlepeer-review

5 Citations (Scopus)


Recently, the cross-correlation between E- and B-mode polarization of the cosmic microwave background, which is well explained by cosmic birefringence with rotation angle β≈0.3 deg, has been found in cosmic microwave background polarization data. We carefully investigate the possibility of explaining the observed EB correlation by the primordial chiral gravitational waves, which can be generated in the parity-violating theories in the primordial Universe. We found that the chiral gravitational wave scenario does not work due to the overproduction of the BB autocorrelation, which far exceeds the observed one by SPTPol and POLARBEAR.

Original languageEnglish
Article number103529
JournalPhysical Review D
Issue number10
Publication statusPublished - 2022 Nov 15

ASJC Scopus subject areas

  • Nuclear and High Energy Physics


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