Abstract
We search for evidence of parity-violating physics in the Planck 2018 polarization data and report on a new measurement of the cosmic birefringence angle . The previous measurements are limited by the systematic uncertainty in the absolute polarization angles of the Planck detectors. We mitigate this systematic uncertainty completely by simultaneously determining and the angle miscalibration using the observed cross-correlation of the - and -mode polarization of the cosmic microwave background and the Galactic foreground emission. We show that the systematic errors are effectively mitigated and achieve a factor-of-2 smaller uncertainty than the previous measurement, finding (68% C.L.), which excludes at 99.2% C.L. This corresponds to the statistical significance of .
- Received 9 August 2020
- Revised 29 September 2020
- Accepted 19 October 2020
DOI:https://doi.org/10.1103/PhysRevLett.125.221301
© 2020 American Physical Society
Physics Subject Headings (PhySH)
synopsis
Hints of Cosmic Birefringence?
Published 23 November 2020
A new analysis of the cosmic microwave background shows that its polarization may be rotated by exotic effects indicating beyond-standard-model physics.
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