Disentangling Cosmology from Observational Artifacts

Presenters:

• Kyle Dawson - Professor - Department of Physics and Astronomy at the University of Utah.

• Tyler Hagen - Ph.D. Candidate at the University of Utah.

Time: 11 AM CT / 12PM ET

Venue: Zoom and in person at the University of Utah (WEB 3780 - Evans Conference room in SCI)

Abstract:

The Dark Energy Spectroscopic Instrument (DESI) has concluded three years of observation, leading to the largest spectroscopic galaxy sample ever produced. In combination with other cosmological probes, these measurements reveal hints of new physics beyond the standard cosmological model. In this talk, we will first present the observations and key measurements that led to these new constraints. We will then describe the roles that neural networks and random forests play in this analysis, and our tests of these machine learning algorithms against more physically motivated linear models.

Speaker Bios

Kyle Dawson is an observational cosmologist using spectroscopic samples of galaxies and quasars to constrain the nature of dark energy and of cosmology more generally.  Since arriving at the University of Utah as an Assistant Professor in 2009, he has played major roles in the Baryon Oscillation Spectroscopic Survey (BOSS), extended Baryon Oscillation Spectroscopic Survey (eBOSS), and, most recently, as co-Spokesperson from 2020-2024 for the scientific collaboration behind the Dark Energy Spectroscopic Instrument (DESI).

Tyler Hagen is a Ph.D. Candidate in the Department of Physics & Astronomy at the University of Utah. Before joining Utah's graduate program in 2021, he received his Bachelor of Science in Physics from Minnesota State University. Tyler is also a member of the DESI Collaboration, in which he is studying the relationship between star-forming galaxies and their surrounding dark matter.