Revealing Cosmic Rotation
  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. In this paper we show that $EB$ correlations-based
estimator is the best for upcoming polarization experiments. The $EB$ based
estimator surpasses other estimators because it has the smallest noise and of
all the estimators is least affected by systematics. Current polarimeters are
optimized for the detection of $B$-mode polarization from either primordial
gravitational waves or by large scale structure via gravitational lensing. In
the paper we also study optimization of CMB experiments for the detection of
cosmological birefringence, in the presence of instrumental systematics, which
by themselves are capable of producing $EB$ correlations; potentially mimicking
CB.
