UCLA

JWST has begun to reveal the nature of the small-scale structures of our Universe at unprecedented distances, probing an era of galaxy formation with remarkably different properties. This has offered the opportunity for novel tests of our models of cosmology and galaxy formation. In this thesis, I focused on a defining characteristic of ΛCDM structure formation, the streaming velocity, which has a variety of impacts on small-scale structure. Specifically, I developed models of and observational predictions for a new class of small-scale structures called SIGOs derived from this mechanism, with the aim of enabling future detections of these objects that would place constraints on alternative cosmologies. I also showed that--in contrast to previous expectations--the streaming velocity enhances star formation on a per-galaxy basis in the dwarf regime at high redshifts. Taken together, I showed that the streaming velocity has significant influence on high-redshift small-scale structure formation, and may serve as an important signal of our standard cosmology.