Wed, November 19, 2025
3:00 pm - 4:00 pm
PRB M2015
Speaker: Zachery Brown (KSU)
Title: Simulation based inference with DESI
Abstract: We characterize the clustering properties of galaxies observed by the Dark Energy Spectroscopic Instrument (DESI) by computing the configuration space two-point and three-point correlation functions. Employing a simulation based emulator technique, we use these clustering statistics to constrain cosmological models. Here, we present two such analyses. The first probes the physics of the inflationary epoch by measuring the presence of primordial non-Gaussianity in the clustering of DESI tracers. Expressed as the quadratic correction to a Gaussian random field, the parameter fNL is measured to a precision of fNL = -3 ^+8 _-10. Secondly, we use our simulation based inference technique to explore the galaxy halo connection. For small scale clustering, we forecast the ability to constrain halo occupation distribution (HOD) models. We then discuss the implications of these forecasts for upcoming surveys such as DESI-II, the Roman Space Telescope, and potential Spec-V surveyors.