First Galaxies as Probes of Dark Matter Physics

In hierarchical models of structure formation, the first galaxies form in low mass dark matter potential wells, probing the behavior of dark matter on kiloparsec (kpc) scales. Even though these objects are not observed today, next-gen telescopes such as JWST and RST will soon offer an observational window into this emergent world. In this talk, I compare and contrast how the first galaxies are assembled in cold, warm, and `fuzzy' dark matter models of cosmology. In `Fuzzy' dark matter (FDM) the dark matter particle is an ultralight ~10^-22 eV boson and the primordial stars are expected to form along dense dark matter filaments. Using a first-of-its-kind cosmological hydrodynamical simulation, we explore the interplay between baryonic physics and unique wavelike features inherent to FDM, and show how the high-redshift universe would look distinctly different from cold and warm dark matter models how next-gen observations will offer new constraints and possibly smoking-gun signatures