Dark Energy Survives: New Study Dismisses Supernova Age Bias Claim

The study published on June 11, 2026, in Monthly Notices of the Royal Astronomical Society was led by Dr. Phil Wiseman of the University of Southampton and co-authored by Nobel laureates Adam Riess and Brian Schmidt. It directly rebuts the late-2025 claim by Yonsei University researchers (led by Young-Wook Lee) that dark energy was weakening and cosmic expansion was no longer accelerating .

The core error the South Korean team made was incorrectly assuming that the age of a galaxy is equivalent to the age of the star that exploded as a Type Ia supernova . Here is the nature of the analytical mistake:

• Galaxy age ≠ supernova progenitor age: The Yonsei team argued that as the universe aged, Type Ia supernovae had systematically different maximum brightnesses, which they attributed to the age of the host galaxy. The new study found that this assumption was flawed — the age of the galaxy cannot simply be equated to the age of the particular white-dwarf star that exploded .
• Negligible or already-corrected effects: The rebuttal shows that the claimed supernova progenitor-age dependence, the redshift-dependent age difference, and their combined cosmological impact are either negligible or rely on effects that are already corrected for in modern supernova analyses . The Yonsei analysis also omitted the standardization step that accounts for these variations .
• Conclusion: Once the age assumption is properly handled, the evidence for accelerating cosmic expansion and the existence of dark energy remains robust .