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New study upholds cosmic acceleration, disputing previous slowdown claims

Astrophysicists re-examined supernova data, concluding that standard measurements of dark energy and cosmic expansion remain reliable.

The short version

  • An international team of astrophysicists published research concluding the expansion of the universe is continuing to accelerate.
  • The findings challenge a 2025 study by South Korean researchers that suggested cosmic expansion was slowing due to weakening dark energy.
  • Researchers identified methodological flaws in the previous study related to stellar age estimates and host galaxy mass accounting.
  • Scientists note that while cosmic acceleration remains supported by the data, the exact nature of dark energy remains unknown.

Key facts

  • An international research team led by the University of Southampton published a study in Monthly Notices of the Royal Astronomical Society affirming that the universe's expansion is accelerating.[ScienceDaily]
  • The study directly disputes a paper published the previous year by South Korean researchers, which argued that dark energy might be weakening and cosmic expansion slowing.[ScienceDaily]
  • The research team found that the earlier study improperly equated galaxy age with the age of exploding stars and failed to correctly calibrate for host galaxy mass.[ScienceDaily]
  • Nobel Laureates Adam Riess and Brian Schmidt, who originally helped discover cosmic acceleration using Type Ia supernovae, co-authored the new analysis.[ScienceDaily]

What remains uncertain

  • The physical identity and fundamental nature of dark energy remain unknown.[ScienceDaily]

Sources