Speaker: Tanveer Karim, PhD, Postdoctoral Fellow at the David A. Dunlap Department of Astronomy & Astrophysics, University of Toronto, and a member of the Dark Energy Spectroscopic Instrument (DESI) collaboration and the Dark Energy Science Collaboration (DESC).

Abstract: Over the past decade, cosmology has encountered significant tensions between different measurements of key cosmological parameters, particularly when comparing the cosmic microwave background (CMB) with data from large-scale structures. Historically, large-scale structure observations have primarily focused on the Universe below redshift 1 using galaxies that are 100-1000 times more massive than our Milky Way. However, ongoing and upcoming surveys, such as the Dark Energy Spectroscopic Instrument (DESI) and the Rubin Observatory, are expanding these measurements beyond redshift 1, opening new avenues for exploration. In this talk, I will discuss the exciting opportunities and the challenges of probing the Universe at 𝑧 ≥ 1 using wide-field surveys of star-forming and less massive galaxies. I will present recent results from the cross-correlation of DESI Legacy Imaging Surveys’ Emission-Line Galaxies with Planck CMB lensing and contextualize reasons for various apparent tensions.