Revealing Cosmic Rotation

Understand

Cosmological Birefringence (CB), a rotation of the polarization plane of radiation coming to us from distant astrophysical sources, may reveal parity violation in either the electromagnetic or gravitational sectors of the fundamental interactions in nature.

• Until only recently this phenomenon could be probed with only radio observations or observations at UV wavelengths.
• Recently, there is a substantial effort to constrain such non-standard models using observations of the rotation of the polarization plane of cosmic microwave background (CMB) radiation.
• This can be done via measurements of the $B$-modes of the CMB or by measuring its TB and EB correlations which vanish in the standard model.