Dark energy, the unknown energy source accelerating the expansion of the universe, doesn't actually exist, according to a new study.
This artist's impression shows the evolution of the universe, starting with the Big Bang on the left and continuing with the emergence of the Cosmic Microwave Background. The formation of the first stars ends the Dark Ages of the universe, followed by the formation of galaxies. Image credit: M. Weiss / Harvard-Smithsonian Center for Astrophysics.
Dark energy is generally thought to be a weak antigravity that acts independently of matter and accounts for about two-thirds of the mass-energy density of the universe.
The lambda cold dark matter (ΛCDM) model, which has served as the standard cosmological model for a quarter of a century, requires dark energy to explain the observed acceleration in the expansion rate of the universe.
Astrophysicists base this conclusion on measurements of distances to supernova explosions in distant galaxies, which appear to be farther away than they should be if the expansion of the universe is not accelerating.
However, the current expansion rate of the universe is increasingly being questioned by new observations.
First, evidence from the Big Bang's afterglow (cosmic microwave background radiation) shows that the expansion of the early Universe is inconsistent with the current expansion, an anomaly known as the Hubble tension.
Furthermore, in an analysis of new high-precision data from the Dark Energy Spectrometer (DESI), the scientists showed that the ΛCDM model does not fit a model in which dark energy does not remain constant but evolves over time. I discovered it.
Both the Hubble tension and the surprises revealed by DESI are difficult to resolve with models that use the simplistic expansion law of the universe from 100 years ago, or the Friedman equation.
This assumes that the universe expands uniformly on average. It's as if you could put all the cosmic structures in a blender and make a nondescript soup without complex structures.
But the current universe actually contains a complex cosmic web of galaxy clusters of sheets and filaments that surround and thread a vast void.
“Our findings show that dark energy is not needed to explain why the universe appears to be expanding at an accelerating rate,” said Professor David Wiltshire.
“Dark energy is a misidentification of fluctuations in the kinetic energy of expansion, which is not uniform in the blocky universe we actually live in.”
“This study provides compelling evidence that may answer some of the key questions about the quirks of our expanding universe.”
“With new data, the universe's greatest mysteries could be solved by the end of the decade.”
New evidence supports the timescape model of the expansion of the universe, which says dark energy is not needed because the difference in the stretch of light is not a result of the universe's acceleration, but of how it adjusts time and distance. .
An ideal clock in empty space would tick faster than in a galaxy, since gravity slows time down.
This model suggests that the Milky Way's clock is about 35% slower than the same clock at its average location in the large cosmic void. That means billions more years have passed in the void.
This allows for further expansion of the universe, and as such a vast void grows to dominate the universe, it appears to be expanding faster and faster.
“We now have so much data that only in the 21st century can we begin to answer the question of how and why a simple mean expansion law emerges from complexity. ” said Professor Wiltshire.
“A simple law of expansion consistent with Einstein's theory of general relativity does not need to obey Friedman's equation.”
“ESA's Euclid satellite, launched in July 2023, has the ability to test and differentiate the Friedman equation from timescape alternatives.”
“However, this will require at least 1,000 independent high-quality supernova observations.”
of study Published in Monthly Notices of the Royal Astronomical Society: Letters.
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antonia seifert others. 2025. Supernovae are evidence of fundamental changes in cosmological models. MNRASL 537 (1): L55-L60;doi: 10.1093/mnrasl/slae112
Source: www.sci.news
