The connection between galaxies and dark matter halos

According to the current paradigm of galaxy formation, galaxies form and evolve in dark matter halos that grow through gravitational collapse of small initial fluctuations in the cosmic density field. Not only are they hosts of galaxies, but dark matter halos are also tracers of the large-scale structure of the Universe. Thus they are crucial components for understanding how galaxies form and evolve in and with the cosmic web. This dissertation is a systematic investigation of the galaxies and gas in the cosmic web, which was published into six first-author papers of mine and seven more papers that I contributed, using observational data of large galaxy surveys such as SDSS and CMB maps such as the Planck, simulations, and modellings. Specifically, I have identified dark matter halos in the low-redshift Universe and constructed the largest to date all-sky group catalog. I also investigated correlations between many of …