Estimating the angular power spectrum of the gravitational-wave
  background in the presence of shot noise
  There has been much recent interest in studying anisotropies in the
astrophysical gravitational-wave (GW) background, as these could provide us
with interesting new information about galaxy clustering and large-scale
structure. However, this information is obscured by shot noise, caused by the
finite number of GW sources that contribute to the background at any given
time. We develop a new method for estimating the angular spectrum of
anisotropies, based on the principle of combining statistically-independent
data segments. We show that this gives an unbiased estimate of the true,
astrophysical spectrum, removing the offset due to shot noise power, and that
in the limit of many data segments, it is the most efficient (i.e.
lowest-variance) estimator possible.
