Fisher matrix predictions for detecting the cosmological 21 cm signal
  with the Ooty Wide Field Array (OWFA)
  We have used the Fisher matrix formalism to quantify the prospects of
detecting the z = 3.35 redshifted 21-cm HI power spectrum with the upcoming
radio-imterferometric array OWFA. OWFA's frequency and baseline coverage spans
comoving Fourier modes (k) in the range 0.018 to 2.7 [1/Mpc]. The OWFA HI
signal, however, is predominantly from the range k below 0.2 [1/Mpc]. The
larger modes, though abundant, do not contribute much to the HI signal. In this
work we have focused on combining the entire signal to achieve a detection. We
find that a 5-sigma detection of A_{HI} is possible with ~ 150 hr of
observations, here A^2 _{HI} is the amplitude of the HI power spectrum. We have
also carried out a joint analysis for A_{HI} and the redshift space distortion
parameter. Our study shows that OWFA is very sensitive to the amplitude of the
HI power spectrum. However, the anisotropic distribution of the k modes does
not make it very suitable for measuring the redshift space distortion
parameter.
