Speaker
Description
The launch of the James Webb Space Telescope (JWST) has ignited a revolution in our understanding of the early universe. Its exquisite infrared capabilities have allowed observers to measure the stellar masses of galaxies, as well as to find them at higher redshifts than ever before. I will describe how, intriguingly, observations in these two arenas appear to be in tension with our models. First, I will discuss the ultra-massive galaxy candidates recently argued to “break” our cosmological model (LCDM). I will show how HST observations at the same redshifts rule out the required departures from LCDM, disfavoring a cosmological explanation of their abundances. I will also briefly discuss the higher-than-expected abundance of z>10 galaxies in JWST, and how clustering measurements can break degeneracies in our models and inform the pathway to form the first galaxies.
