Cosmology results from 3 years of DESI
Prof. Dr. Seshadri Nadathur (University of Portsmouth, UK)

More than 25 years after the discovery of the accelerated expansion of the Universe, understanding dark energy remains the biggest open problem in cosmology. The Dark Energy Spectroscopic Instrument (DESI) is the first of a new generation of “Stage-IV” cosmology survey experiments aiming to improve this understanding. By precisely mapping the positions of over 50 million galaxies and quasars, DESI is measuring the expansion history of the Universe over the last 11 billion years. I will describe the experiment and discuss the cosmological results from the first 3 years of data, from baryon acoustic oscillations (BAO) and the full shape of the clustering power spectrum. These include exciting hints of an anomaly in the cosmological constant model of dark energy, and unprecedented constraints on the neutrino mass scale. I will describe the nature of the data constraints and comment on the implications for fundamental physics models.