Yale Astronomy Colloquium - Wendy Freedman

Event time: 
Thursday, March 6, 2025 - 2:30pm
Speaker: 
Wendy Freedman
Speaker Institution: 
University of Chicago
Talk Title: 
Does Our Standard Cosmological Model Need Revision?
Event description: 

The question of whether there is new physics beyond our current standard model, Lambda Cold Dark Matter (LCDM) remains an unresolved issue in cosmology today. Recent measurements of the Hubble constant (Ho) using Cepheids and Type Ia supernovae (SNe) appear to differ significantly, with claims of up to 6-sigma, from values inferred from the cosmic microwave background (CMB) fluctuations. This tension, if real, could indicate new physics beyond the standard model. I will give a status report on our Chicago Carnegie Hubble Program (CCHP) measuring Ho and present new results from  James Webb Space Telescope (JWST). Over a period of decades, we  have developed three independent methods for measuring the distances to nearby galaxies that provide a calibration for SNe: Tip of the Red Giant Branch (TRGB) stars, J-Region Asymptotic Giant Branch (JAGB) stars and Cepheid variables. 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.

Location: 
Kline Tower, Room 205 See map
219 Prospect Street
New Haven, CT 06511