Overview
- The peer‑reviewed analysis in Monthly Notices of the Royal Astronomical Society reexamines Type Ia supernova distances using about 300 host galaxies to account for progenitor‑age effects.
- After applying the correction, the supernova data no longer favor the ΛCDM model and instead fit scenarios in which dark energy weakens over time when combined with BAO and CMB results.
- The study reports that younger‑progenitor supernovae appear dimmer and older‑progenitor events brighter, with the bias detected at a stated 99.999% confidence.
- The authors say the corrected data imply the cosmos has entered a decelerated expansion phase, though outside experts caution the result needs independent verification.
- The team is running a “no‑evolution” cross‑check now, and forthcoming Vera C. Rubin Observatory surveys targeting roughly 20,000 new supernova hosts could deliver decisive tests within about five years.