Title: Charaterizing Cosmic Acceleration with Geometric Probes from Galaxy Surveys

Speaker：Qinxun Li

 

The underlying physics of cosmic acceleration remains one of the most profound mysteries in cosmology after almost three decades since its discovery from Type Ia supernovae. Galaxy surveys, such as Sloan Digital Sky Survey (SDSS) and Dark Energy Spectroscopic Instrument (DESI), have provided us with independent evidence for cosmic acceleration. Moreover, recent DESI DR2 measurements of Baryon Acoustic Oscillations (BAO) have revealed a $\sim 3\sigma$ hint of a deviation from the standard $\Lambda$CDM model. In this talk, I will first introduce the BAO measurement from galaxy surveys and its implications for cosmic acceleration. Then, I will present a novel geometric probe, the kinematic lensing ratio (KiLeR), and discuss its potential for characterizing cosmic acceleration. 

 

Qinxun Li is a PhD candidate at University of Utah. His research focuses on the measurement of Baryon Acoustic Oscillations (BAO) from large-scale structure surveys. He is actively involved with DESI, especially the galaxy/quasar clustering working group, and co-leads the BAO topical group. Besides BAO, he is also interested in multiple cosmological probes, such as redshift-space distortions (RSD) and weak lensing.