All articles tagged with #cosmic acceleration
A reanalysis of Pantheon+ Type Ia supernovae, including a correction for the ages of progenitor stars, finds the cosmic expansion may be slowing instead of accelerating and that the apparent acceleration varies with direction. This challenges the dark energy paradigm, though other studies still support acceleration. The Rubin Observatory’s LSST is expected to provide a decisive test with a much larger supernova sample.
Southampton researchers re-analyze a 2025 Yonsei claim that the universe’s expansion isn’t accelerating and find the result was a false alarm. After correcting for galaxy-mass calibration and local stellar ages in Type Ia supernovae, the data remain consistent with an accelerating universe and dark energy remains needed. The Yonsei team still argues age effects matter in some analyses, but the broader cosmology community will gain more decisive data from upcoming surveys like the Vera Rubin Observatory to settle the issue.
A new MNRAS analysis reinforces that the universe’s expansion is still accelerating, countering a recent paper that argued measurement biases could mimic deceleration; after recalibrating for stellar ages, host-galaxy mass, and environmental factors, the results remain consistent with ongoing cosmic acceleration, underscoring the Big Freeze fate while highlighting ongoing scientific scrutiny of dark energy.
A new study proposes that the universe's accelerating expansion can be explained by a modified geometry of spacetime, called Finsler geometry, without invoking dark energy, by allowing measurements to depend on direction and velocity, which could reshape our understanding of cosmic dynamics.