Hamsa Padmanabhan - February 3, 2017

A halo model for cosmological neutral hydrogen

The evolution of neutral hydrogen (HI) across redshifts is a powerful
probe of cosmology, large scale structure in the universe and the
intergalactic medium. We build an analytical halo model to describe
the distribution of HI in the post-reionization universe (z ~ 5 to 0).
We obtain the best-fitting parameters from a rich sample of
observational data: low redshift 21-cm emission line studies,
intermediate redshift intensity mapping experiments, and higher
redshift Damped Lyman Alpha (DLA) observations.  Our model describes
the abundance and clustering of neutral hydrogen across redshifts 0 -
5, and is a useful tool for investigating different aspects of galaxy
evolution as well as in the current and future intensity mapping
experiments.