Measuring Cosmic Sound with the Dark Energy Spectroscopic Instrument

  • Physics and Astronomy Colloquium

May 16, 2025 3:30 PM - May 16, 2025 4:30 PM
PAIS 1100

Host:
Dinesh Loomba
Presenter:
Daniel Eisenstein (Harvard)
Video recording
I will describe recent results from the Dark Energy Spectroscopic Instrument (DESI) on the measurement of the cosmic distance scale with the baryon acoustic oscillation (BAO) method and its resulting implications for cosmology and dark energy.  I'll start with an introduction to BAO physics and its use as a cosmological standard ruler, as well as to the design and status of the DESI project.  Then I'll turn to the results from the first three years of data, which provide sub-percent measurements of cosmological distance and a tantalizing suggestion of a breakdown of the cosmological constant model.  Cosmology is no longer at a moment of concordance, and I will close by attempting to summarize the current state of play.