Date: Wednesday 02-Apr-2025
Time: 11:30-12:30 pm
Location: PSC 1136
Speaker: Johannes U. Lange (American University)
Title: Cosmic tensions in the DESI era: Is lensing still low?
Abstract: Recent cosmology experiments have uncovered several potential tensions in our standard model of the Universe. These findings, including the well-known Hubble tension and new evidence for time-evolving dark energy, indicate that we may be at the cusp of transforming our view of the Universe. In this talk, I will discuss the so-called lensing-is-low problem, the finding that the measured gravitational lensing amplitude around massive galaxies is smaller than expected from dark matter simulations. Since its first discovery around a decade ago, we have made significant advances in our understanding of cosmic large-scale structure and galaxy formation. Similarly, we now have access to much larger data sets such as new measurements from the Dark Energy Spectroscopic Instrument (DESI) and stage-III weak lensing surveys such as the Dark Energy Survey (DES) and the Kilo-Degree Survey (KiDS). In this talk, I will present new results from recent DESI, DES, and KiDS data on the potential origin of the lensing-is-low problem. By examining this new data, I will discuss whether we are closer to resolving this issue or whether it continues to challenge our standard model of the Universe.
Guidelines and format for the CTC Lunch seminars.
Past CTC Lunch seminars.
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SPECIAL ACCOMMODATIONS:
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