New analysis says universe is still expanding faster, dark energy holds

A high-profile claim that dark energy might have been an illusion has been pushed back after a University of Southampton analysis found the challenge did not hold up. The new study says the universe is still expanding at an accelerating rate, preserving the standard cosmological picture that has guided nearly 30 years of research.

The controversy began when astronomers argued that the long-used supernova method for measuring cosmic expansion had fundamental flaws. Their late-2025 claim raised a startling possibility: that the acceleration seen across decades of observations was not real. The Southampton team revisited the evidence and concluded that the earlier paper made key mistakes in the way it handled the supernova data, leaving the conventional measurements intact.

That matters because supernovae have been central to one of modern physics’ biggest discoveries. The new analysis includes Nobel Prize winners Adam Riess and Brian Schmidt, whose earlier work helped establish that the universe’s expansion is speeding up. Had the challenge survived scrutiny, it would have forced researchers to reconsider a result that has shaped cosmology for almost three decades.

Instead, the study narrows the debate back to the harder question: not whether the universe is accelerating, but what is causing that acceleration. Lead author Phil Wiseman said the team had “averted this crisis,” a line that captures how close cosmology came to a major reversal and how important the reanalysis was for testing a bold claim against the full body of evidence.

The broader message is one of science correcting itself in public. A provocative theory did what such theories should do: it forced researchers to check the measurements again, probe the assumptions, and see whether the result could survive another round of scrutiny. In this case, it did. The universe still appears to be expanding faster, dark energy still dominates the cosmic outlook, and the mystery that remains is not whether the force exists, but what it is.

That keeps dark energy among the most important unresolved problems in physics. The existential doubt has eased, but the central question remains open, and that is exactly where serious cosmology now stands.