Researchers analyze more than 1,700 Type Ia supernovae and report results that challenge the standard interpretation that the universe’s expansion is accelerating. The study argues that after accounting for the ages of the stars that produce these explosions, the data can be explained by cosmic expansion slowing rather than speeding up. It also reports that the apparent acceleration varies with direction, which the authors say would be difficult to reconcile with a simple dark-energy explanation.
The findings are presented as a potential problem for the current dark-energy framework, but the conclusion is disputed by other researchers. The Slashdot summary points to a separate paper co-authored by Professor Maria Vincenzi at the University of Oxford that concludes existing observations still support an accelerating universe. The dispute centers on how supernova properties and analysis choices affect the inferred expansion history. Multiple outlets frame the debate as unresolved and describe upcoming observations from next-generation facilities as a key test of whether cosmic acceleration is genuine.
The study is published in *Monthly Notices of the Royal Astronomical Society*.
