Evolution of baryons in the high-redshift universe

Hamsa Padmanabhan
December 15, 2017 - 12:15pm


The evolution of neutral hydrogen (HI) across redshifts is a powerful

probe of cosmology, large scale structure in the universe and the

intergalactic medium. Using a data-driven 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 useful for investigating

different aspects of galaxy evolution and for comparison with

hydrodynamical simulations. I will discuss (i) forecasting future

observations with neutral hydrogen and (ii) extensions to the model for

the case of carbon monoxide intensity mapping at moderate redshifts.