New Delhi: The universe could be nearly twice as old as scientists currently estimate, according to an alternative cosmological model developed by researchers at the University of Ottawa in Canada.
The model, called Covarying Coupling Constants plus Tired Light (CCC+TL), puts the age of the universe at 26.7 billion years, compared with the widely accepted estimate of 13.8 billion years. It also proposes that some phenomena attributed to dark matter and dark energy could instead be explained by changes in fundamental physical constants.
The model was developed by Rajendra Gupta, an adjunct professor in the university’s Department of Physics. Along with postdoctoral researcher Nikolaos Samaras, he has been testing it against several major cosmological observations.
In their latest study, published in the journal Universe in June 2026, the researchers examined whether the model could reproduce the abundance of light elements formed shortly after the Big Bang, in a process known as Big Bang nucleosynthesis.
The University of Ottawa announced the findings on 6 November.
Challenging the standard cosmological model
The prevailing cosmological model, known as Lambda Cold Dark Matter (ΛCDM), explains the universe’s evolution through ordinary matter, dark matter and dark energy.
However, the CCC+TL model proposes that fundamental physical constants change together over time, while light also loses some energy as it travels through space — an idea known as ‘tired light’.
“Most emerging models explain only a limited set of observations,” Gupta said.
He added that an alternative model must remain consistent with established cosmological observations, including those concerning the early universe.
The researchers found that, under specific assumptions about how physical processes scale over time, their model reproduced the standard model’s predictions for the primordial abundances of helium and other light elements.
However, the result depended on assumptions that nuclear reaction rates and neutron decay rates change in step with the universe’s expansion rate.
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Explaining galaxies without dark matter
In separate studies published later, the researchers applied their framework to the rotation of 175 galaxies and the Bullet Cluster, a system of colliding galaxy clusters commonly cited as evidence for dark matter.
They reported that their model could reproduce certain gravitational effects without requiring invisible matter.
“Observations attributed to dark matter and dark energy likely originate from covarying coupling constants,” Gupta said.
The researchers also suggested that their model could explain why the James Webb Space Telescope has detected unexpectedly developed galaxies in the early universe.
Under CCC+TL, galaxies observed at the same redshift would have had considerably more time to develop.
“Impossible early galaxies become predictable galaxies,” Gupta said.
More time for early galaxies to form
The researchers also argue that their model could help explain why the James Webb Space Telescope (JWST) has detected unexpectedly large and developed galaxies in the early universe.
Under CCC+TL, galaxies observed at the same redshift would have had considerably more time to develop.
“Impossible early galaxies become predictable galaxies,” Gupta said.
The findings remain theoretical, and CCC+TL has not replaced the standard cosmological model.
The researchers describe their work as an early proof of concept that warrants further investigation.
(Edited by Maryam Hassan)