Add to Calendar 2026-04-02T16:00:00 2026-04-02T17:00:00 Measuring dark energy and H0 with DESI Event Information: Abstract: The Dark Energy Spectroscopic Instrument (DESI) is the first of a new generation of Dark Energy experiments, and probes evolution in the universe using galaxy clustering. Within the galaxy clustering signal, the projected location of the Baryon Acoustic Oscillations (BAO) acts as a standard ruler to map cosmic evolution. I will present the latest BAO results from the DESI Data Release 2 (DR2) sample, which contains 3 years of data, and their impact on our understanding of dark energy and neutrino masses. I will explain some of the difficulties in expanding this work to model the full clustering signal, and the work underway to provide more robust results. Finally, I will consider how the amplitude of the BAO signal can help us measure the Hubble constant, providing an independent measurement from energy densities rather than evolutionary dynamics.  Bio: Will Percival is an observational cosmologist whose research interests focus on the properties of the Universe on the largest scales. Surveys of three-dimensional galaxy positions provide a wealth of data both on the physics just after the Big-Bang when the seed fluctuations that will grow through gravity to become galaxies were created, and on the physics driving the evolution of the Universe today.   Learn More: See his faculty webpage: https://uwaterloo.ca/physics-astronomy/profile/wpercivaSee his faculty bio page: https://uwaterloo.ca/scholar/wperciva Read UofWaterloo articles:  "Will Percival named Royal Society of Canada Fellow": https://uwaterloo.ca/science/news/will-percival-named-royal-society-canada-fellow Peering into the cosmos: https://uwaterloo.ca/news/global-futures/peering-cosmos Read Perimeter Institute article "Will Percival named among the world's most influential scientists": https://perimeterinstitute.ca/news/will-percival-named-among-worlds-most-influential-scientists  See him on Youtube: https://www.youtube.com/watch?v=VeZfktef0VE https://www.youtube.com/watch?si=hNZ9toTiBKqny4BA&v=Qg99WsPa7KY&feature=youtu.be 2025 New Royal Society of Canada Fellow: https://www.youtube.com/watch?v=TCOGYSo3NXM  Resources: The Dark energy Spectroscopic Instrument (DESI): https://www.desi.lbl.gov/ About Dark energy: https://science.nasa.gov/dark-energy/ About Baryon Acoustic Oscillations (BAO): https://sci.esa.int/web/euclid/-/what-are-baryonic-acoustic-oscillations- What is the Hubble constant: https://science.nasa.gov/mission/hubble/science/science-behind-the-discoveries/hubble-constant-and-tension/   Event Location: HENN 201