How do Galaxies Accrete Gas and Form Stars?
  Great strides have been made in the last two decades in determining how
galaxies evolve from their initial dark matter seeds to the complex structures
we observe at z=0. The role of mergers has been documented through both
observations and simulations, numerous satellites that may represent these
initial dark matter seeds have been discovered in the Local Group, high
redshift galaxies have been revealed with monstrous star formation rates, and
the gaseous cosmic web has been mapped through absorption line experiments.
Despite these efforts, the dark matter simulations that include baryons are
still unable to accurately reproduce galaxies. One of the major problems is our
incomplete understanding of how a galaxy accretes its baryons and subsequently
forms stars. Galaxy formation simulations have been unable to accurately
represent the required gas physics on cosmological timescales, and observations
have only just begun to detect the star formation fuel over a range of
redshifts and environments. How galaxies obtain gas and subsequently form stars
is a major unsolved, yet tractable problem in contemporary extragalactic
astrophysics. In this paper we outline how progress can be made in this area in
the next decade.
