An Improved Treatment of Cosmological Intergalactic Medium Evolution
  The modeling of galaxy formation and reionization, two central issues of
modern cosmology, relies on the accurate follow-up of the intergalactic medium
(IGM). Unfortunately, owing to the complex nature of this medium, the
differential equations governing its ionization state and temperature are only
approximate. In this paper, we improve these master equations. We derive new
expression for the distinct composite inhomogeneous IGM phases, including all
relevant ionizing/recombining and cooling/heating mechanisms, taking into
account inflows/outflows into/from halos, and using more accurate recombination
coefficients. Furthermore, to better compute the source functions in the
equations we provide an analytic procedure for calculating the halo mass
function in ionized environments, accounting for the bias due to the ionization
state of their environment. Such an improved treatment of IGM evolution is part
of a complete realistic model of galaxy formation presented elsewhere.
