Galaxy Evolution at High Redshift: Obscured Star Formation, GRB Rates,
  Cosmic Reionization, and Missing Satellites
  We provide an holistic view of galaxy evolution at high redshift z>4, that
incorporates the constraints from various astrophysical/cosmological probes,
including the estimate of the cosmic SFR density from UV/IR surveys and long
GRB rates, the cosmic reionization history after the latest Planck
measurements, and the missing satellites issue. We achieve this goal in a
model-independent way by exploiting the SFR functions derived by Mancuso et al.
(2016) on the basis of an educated extrapolation of the latest UV/far-IR data
from HST/Herschel, and already tested against a number of independent
observables. Our SFR functions integrated down to an UV magnitude limit
M_UV<-13 (or SFR limit around 10^-2 M_sun/yr) produces a cosmic SFR density in
excellent agreement with recent determinations from IR surveys and, taking into
account a metallicity ceiling Z<Z_sun/2, with the estimates from long GRB
rates. They also yield a cosmic reionization history consistent with that
implied by the recent measurements of the Planck mission on the electron
scattering optical depth tau_es~0.058; remarkably, this result is obtained
under a conceivable assumption regarding the average value f_esc~0.1 of the
escape fraction for ionizing photons. We demonstrate via the abundance matching
technique that the above constraints concurrently imply galaxy formation to
become inefficient within dark matter halos of mass below a few 10^8 M_sun;
pleasingly, such a limit is also required not to run into the missing satellite
issue. Finally, we predict a downturn of the galaxy luminosity function
faintward of M_UV<-12, and stress that its detailed shape, as plausibly probed
in the next future by the JWST, will be extremely informative on the
astrophysics of galaxy formation in small halos, or even on the microscopic
nature of the dark matter.
