Effects of large-scale environment on the assembly history of central
  galaxies
  We examine whether large-scale environment affects the mass assembly history
of their central galaxies. To facilitate this, we constructed dark matter halo
merger trees from a cosmological N-body simulation and calculated the formation
and evolution of galaxies using a semi-analytic method. We confirm earlier
results that smaller halos show a notable difference in formation time with a
mild dependence on large-scale environment. However, using a semi-analytic
model, we found that on average the growth rate of the stellar mass of central
galaxies is largely insensitive to large-scale environment. Although our
results show that the star formation rate (SFR) and the stellar mass of central
galaxies in smaller halos are slightly affected by the assembly bias of halos,
those galaxies are faint, and the difference in the SFR is minute, and
therefore it is challenging to detect it in real galaxies given the current
observational accuracy. Future galaxy surveys, such as the BigBOSS experiment
and the Large Synoptic Survey Telescope, which are expected to provide
observational data for fainter objects, will provide a chance to test our model
predictions.
