Tue Dec 30 00:00:00 UTC 2025: Here’s a summary of the text and a news article based on it:
Summary:
A new study from Yonsei University in South Korea challenges the standard cosmological model, Lambda-Cold Dark Matter (LCDM), which posits an accelerating expansion of the universe. The study suggests that the expansion is slowing down due to weakening dark energy. This contradicts the prevailing view that dark energy is a constant force driving galaxies apart. The findings, which align with data from the Dark Energy Spectroscopic Instrument (DESI), have sparked a debate within the cosmology community. While some experts remain skeptical, citing issues with the study’s methodology and data interpretation, others acknowledge that if validated, the findings could necessitate a revision of the current cosmological model. Researchers are now looking to future instruments like the Vera Rubin Observatory and the Nancy Grace Roman space telescope for further insights into dark energy and the fate of the universe.
News Article:
Universe’s Expansion May Be Slowing, Challenging Standard Cosmology
KOCHI, December 30, 2025 – A groundbreaking study from Yonsei University in South Korea suggests the expansion of the universe, long believed to be accelerating due to the mysterious force known as dark energy, may actually be slowing down. The research, published in the Notices of the Royal Astronomical Society, directly contradicts the widely accepted Lambda-Cold Dark Matter (LCDM) model, which describes an accelerating universe driven by constant dark energy.
According to the LCDM model, dark energy accounts for approximately 70% of the cosmos and pushes galaxies apart at an ever-increasing rate. However, the new study proposes that dark energy is weakening, putting the brakes on this acceleration.
“Our study shows that the universe has already entered a phase of decelerated expansion at the present epoch and that dark energy evolves with time much more rapidly than previously thought,” said Professor Young-Wook Lee, who led the research.
The findings are supported by data from the Dark Energy Spectroscopic Instrument (DESI) that suggest the so-called standard candles used to measure cosmic distances, Type Ia supernovae, may not be as reliable as previously thought. The study indicates that the luminosity of these supernovae could be affected by the age of their parent stars.
The implications of this study are significant. If confirmed, it would force scientists to re-evaluate our understanding of the universe’s fundamental forces and its ultimate destiny. Instead of continuing to expand indefinitely, the universe may eventually contract in a “Big Crunch.”
The study has ignited a debate among cosmologists. Dragan Huterer, a cosmologist at the University of Michigan expressed doubts stating that although the statistical significance of the findings is strong, but not sufficiently strong to claim a discovery and the need to collect and analyze more data.
Brian Schmidt, one of the three astrophysicists awarded the 2011 Nobel Prize for his work on dark energy, remains skeptical about the study’s consequences for the LCDM.
“If validated, these findings would not negate the (standard) model of the cosmos, but would modify it,” Prof. Schmidt wrote in an email.
Adam Riess, also a 2011 Nobel laureate, believes the Yonsei University study doesn’t hold water saying it arises from a very particular way of slicing the data and from assumptions that aren’t consistent with how supernova cosmology is done today.”
Cosmologists are now looking towards next-generation observatories, such as the Vera Rubin Observatory in Chile and NASA’s Nancy Grace Roman Space Telescope, to provide further insights into the nature of dark energy and the fate of the universe. These instruments promise to deliver more precise measurements of cosmic distances and the expansion rate, potentially resolving the current debate and reshaping our understanding of the cosmos.
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