Cosmology and Galaxy Formation at the Crossroads

We find ourselves at a pivotal era in the study of cosmology and galaxy formation. The dark energy + cold dark matter (ΛCDM) paradigm is firmly established as the default cosmological model, owing in large part to its incredible success in explaining the large-scale distribution of matter and energy in Universe, yet the nature of both dark energy and dark matter remain deep mysteries. The successes of ΛCDM have also focused attention on its potential shortcomings, which may call for minor adjustments to the theory or presage more substantive revisions to our baseline model of the cosmos. I will discuss some of the areas of potential discord between observations and ΛCDM expectations, including JWST results on high-redshift galaxies and measurements of the expansion rate of the Universe. I will also explore how current and forthcoming facilities either will further solidify ΛCDM as the standard cosmological paradigm or signal a paradigm shift in our basic understanding of the Universe.