Searching for stochastic background of ultra-light fields with atomic
  sensors
  We propose a cross-correlation method for the searches of ultra-light fields,
in particular, with a space network of atomic sensors. The main motivation of
the approach is cancellation of uncorrelated noises in the observation data and
unique pattern the fields leave on the cross-spectrum, depending on their
nature (i.e., scalar, vector or tensor). In particular, we analytically derive
a dependence of the cross-spectrum on the angle between two pairs of detectors.
We then confirm obtained angular curves with a numerical simulation. We imply
application of the method to the detection of dark matter and gravitational
waves.
