Lecture by professor Wendy Freedman at the IRMP

 

 Professor Wendy Freedman (University of Chicago), recipient of the Prix Lemaître 2024, will give a lecture at our institute on Friday, May 17, at 11 a.m., in the Auditoire de la Vallée Poussin (CYCL01).

Title: "The Hubble-Lemaître Law: What Have We Learned from HST and JWST?"

Abstract: The question of whether there is new physics beyond our current standard model, Lambda Cold Dark Matter (LCDM), is a crucial unresolved issue in cosmology today. Recent measurements of the Hubble constant (Ho) using Cepheids and Type Ia supernovae (SNe) appear to differ significantly (5-sigma) from values inferred from the cosmic microwave background (CMB) fluctuations. This discrepancy, if real, could indicate new physics beyond the standard model. In this talk, I will review the Hubble Space Telescope results on measuring Ho and present new results from a James Webb Space Telescope. It utilizes three independent methods for measuring the distances to (the same) nearby galaxies that provide a calibration for SNe: Cepheid variables, Tip of the Red Giant Branch (TRGB) stars and J-Region Asymptotic Giant Branch (JAGB) stars. The Near-Infrared Camera on JWST has four times the resolution and ten times the sensitivity of HST in the near infrared, and is critical for ascertaining whether new physics is required beyond the standard model of cosmology.

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Published on May 10, 2024