Measuring the non-Gaussian stochastic gravitational-wave background: a
  method for realistic interferometer data
  A stochastic gravitational-wave background (SGWB) can arise from the
superposition of many independent events. If the rate of events per unit time
is sufficiently high, the resulting background is Gaussian, which is to say
that it is characterized only by a gravitational-wave strain power spectrum.
Alternatively, if the event rate is low, we expect a non-Gaussian background,
characterized by intermittent sub-threshold bursts. Many experimentally
accessible models of the SGWB, such as the SGWB arising from compact binary
coalescences, are expected to be of this non-Gaussian variety. Primordial
backgrounds from the early universe, on the other hand, are more likely to be
Gaussian. Measuring the Gaussianity of the SGWB can therefore provide
additional information about its origin. In this paper we introduce a novel
maximum likelihood estimator that can be used to estimate the non-Gaussian
component of an SGWB signature measured in a network of interferometers. This
method can be robustly applied to spatially separated interferometers with
colored, non-Gaussian noise. Furthermore, it can be cast as a generalization of
the widely used stochastic radiometer algorithm.
