For the previous 3 years, astronomers have actually extensively thought that deep space is broadening at an ever-increasing rate, driven by a hidden phenomenon called dark energy that serves as a type of anti-gravity.

This conclusion, based upon range measurements to distant galaxies utilizing Type Ia supernovae, made the 2011 Nobel Prize in Physics.

Yonsei University’s Professor Young-Wook Lee and coworkers have actually now put forward brand-new proof that Type Ia supernovae, long concerned as the Universe’s ‘basic candle lights,’ are in truth highly impacted by the age of their progenitor stars.

“Our research study reveals that deep space has actually currently gotten in a stage of slowed down growth at today date which dark energy progresses with time far more quickly than formerly believed,” Professor Lee stated.

“If these outcomes are validated, it would mark a significant paradigm shift in cosmology because the discovery of dark energy 27 years earlier.”

Even after luminosity standardization, supernovae from more youthful excellent populations appear methodically fainter, while those from older populations appear brighter

Based upon a much bigger host-galaxy sample of 300 galaxies, the astronomers validated this impact at incredibly high significance (99.999% self-confidence), recommending that the dimming of remote supernovae develops not just from cosmological results however likewise from excellent astrophysics impacts.

When this organized predisposition was remedied, the supernova information no longer matched the Standard ΛCDM cosmological design with a cosmological constant.

Rather, it lined up far much better with a brand-new design preferred by the Dark Energy Spectroscopic Instrument (DESI) job, originated from Baryon Acoustic Oscillations (BAO) and Cosmic Microwave Background (CMB) information.

The fixed supernova information and the BAO+CMB-just results both show that dark energy damages and progresses considerably with time.

When the remedied supernova information were integrated with BAO and CMB outcomes, the Standard ΛCDM design was ruled out with frustrating significance.

A lot of unexpected of all, this combined analysis suggests that deep space is not speeding up today as formerly believed, however has actually currently transitioned into a state of slowed down growth.

“In the DESI task, the essential outcomes were acquired by integrating uncorrected supernova information with baryonic acoustic oscillations measurements, causing the conclusion that while deep space will decrease in the future, it is still speeding up at present,” Professor Lee stated.

“By contrast, our analysis– which uses the age-bias correction– reveals that deep space has actually currently gone into a slowing down stage today.”

“Remarkably, this concurs with what is individually forecasted from BAO-only or BAO+CMB analyses, though this reality has actually gotten little attention up until now.”

To even more validate their outcomes, the scientists are now performing an evolution-free test, which utilizes just supernovae from young, coeval host galaxies throughout the complete redshift variety.

The very first outcomes currently support their primary conclusion.

“Within the next 5 years, with the Vera C. Rubin Observatory finding more than 20,000 brand-new supernova host galaxies, accurate age measurements will enable a much more robust and conclusive test of supernova cosmology,” stated Yonsei University’s Professor Chul Chung.

The group’s paper was released today in the Regular monthly Notices of the Royal Astronomical Society

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Junhyuk Son et al2025. Strong progenitor age predisposition in supernova cosmology– II. Positioning with DESI BAO and indications of a non-accelerating Universe. MNRAS 544 (1 ): 975-987; doi: 10.1093/ mnras/staf1685