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arXiv · 2203.10733

Constraints on cosmic birefringence using $E$-mode polarisation

Arefe Abghari·Raelyn M. Sullivan·Lukas T. Hergt·Douglas Scott
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Abstract

A birefringent universe could show itself through a rotation of the plane of polarisation of the cosmic microwave background photons. This is usually investigated using polarisation $B$ modes, which is degenerate with miscalibration of the orientation of the polarimeters. Here we point out an independent method for extracting the birefringence angle using only temperature and $E$-mode signals. We forecast that, with an ideal cosmic-variance-limited experiment, we could constrain a birefringence angle of $0.3^\circ$ with $3\,\sigma$ statistical significance, which is close to the current constraints using $B$ modes. We explore how this method is affected by the systematic errors introduced by the polarisation efficiency. In the future, this could provide an additional way of checking any claimed $B$-mode derived birefringence signature.

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Arefe Abghari, Raelyn M. Sullivan, Lukas T. Hergt, Douglas Scott. 2022-03-21. Constraints on cosmic birefringence using $E$-mode polarisation. https://doi.org/10.1088/1475-7516%2F2022%2F08%2F033

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