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UID:UW-Physics-Event-9208
DTSTART:20250501T203000Z
DTEND:20250501T213000Z
DTSTAMP:20260413T151505Z
LAST-MODIFIED:20250425T143031Z
LOCATION:4421 Sterling Hall
SUMMARY:What JWST Reveals about the Hubble Tension\, Astronomy Colloqu
 ium\, Adam Riess\, Johns Hopkins University
DESCRIPTION:The Hubble tension—the persistent discrepancy between lo
 cal and early-Universe measurements of the Hubble constant—remains o
 ne of the most intriguing puzzles in cosmology. The James Webb Space T
 elescope (JWST) now offers a fresh perspective on this issue by allowi
 ng an independent look at the same type of stars\, Cepheids\, used in 
 the Hubble Space Telescope (HST) measurements that help define our bes
 t local estimate of cosmic expansion.  I’ll show how early JWST data
 \, although still limited in size\, serves as a powerful crosscheck of
  the HST-based distance ladder. When comparing results across multiple
  techniques and research groups\, we find strong consistency with the 
 HST measurements\, lending confidence to their accuracy. These compari
 sons suggest that the observed tension is unlikely to stem from system
 atic errors in HST’s Cepheid distances. Though JWST’s smaller samp
 le size limits its precision for now\, it already provides valuable va
 lidation of the HST approach. As more data accumulates\, JWST will pla
 y an increasingly important role in testing and refining our understan
 ding of the expanding Universe—and perhaps help us get to the bottom
  of the Hubble tension.
URL:https://www.physics.wisc.edu/events/?id=9208
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