Cosmology from Three Years of DESI (DR2)

• Christophe Yeche (CEA)

Room: 100/-1-A900 - Auditorium Joliot Curie The Dark Energy Spectroscopic Instrument (DESI) is building the largest 3D map of our universe to measure its expansion history over the past 11 billion years, and thereby, study dark energy. Over a five-year period, DESI will spectroscopically classify nearly 40 million galaxies and quasars over 1/3 of the sky and to redshifts z < 3.5.  The DESI collaboration has completed measurements of the baryon acoustic oscillation (BAO) feature and more generally, of large-scale structure, using data from the first three years of observation (DR2). In this seminar, I will present those measurements and their implications for our understanding of the cosmological model, I will discuss the tensions with LambdaCDM and the question of the nature of dark energy.