An analytical method to simulate the HI 21-cm visibility signal for
  intensity mapping experiments
  Simulations play a vital role in testing and validating HI 21-cm power
spectrum estimation techniques. Conventional methods use techniques like N-body
simulations to simulate the sky signal which is then passed through a model of
the instrument. This makes it necessary to simulate the HI distribution in a
large cosmological volume, and incorporate both the light-cone effect and the
telescope's chromatic response. The computational requirements may be
particularly large if one wishes to simulate many realizations of the signal.
In this paper we present an analytical method to simulate the HI visibility
signal. This is particularly efficient if one wishes to simulate a large number
of realizations of the signal. Our method is based on theoretical predictions
of the visibility correlation which incorporate both the light-cone effect and
the telescope's chromatic response. We have demonstrated this method by
applying it to simulate the HI visibility signal for the upcoming Ooty Wide
Field Array Phase I.
