One model, many observations
During 2025 and 2026, Rajendra Gupta, Adjunct Professor in uOttawa’s Department of Physics, and postdoctoral researcher Dr. Nikolaos Samaras tested the CCC+TL model against a range of important astronomical observations.
CCC+TL stands for “covarying coupling constants plus tired light.” The model suggests that what is usually attributed to dark matter and dark energy could instead come from evolving fundamental constants that govern how forces and particles interact.
Scientists have searched for dark matter and dark energy for decades, but neither has been directly detected. The standard cosmological model, known as ΛCDM, also faces questions raised by observations of surprisingly mature galaxies in the early Universe.
“Most emerging models explain only a limited set of observations,” Professor Gupta says. “A new model must not conflict with the pillars of cosmology and astrophysics, and our findings meet that challenge, including the yet-to-be-published Cosmic Microwave Background challenge”
CCC+TL changes the Einstein and Friedmann equations, which describe gravity and the expansion of the Universe. That meant the researchers couldn’t just modify the standard model and existing computer codes. For each test, they developed CCC+TL compliant equations and code.
What the tests found
The model’s results agreed with several major observations. Its predictions for the amounts of hydrogen, helium and other light elements formed shortly after the Big Bang matched those of the standard model. It also agreed with cosmic-chronometer measurements, which use the ages of galaxies to estimate how fast the Universe has expanded over time.
In a recent paper published in Monthly Notices of the Royal Astronomical Society, a prestigious astronomy journal, the researchers also applied the model to all 175 galaxies in the SPARC database and found it could reproduce their rotation curves without dark matter. A separate study of time dilation in supernova observations also supports the model, although that paper is still under review.
The team looked at the Bullet Cluster too. There, the extra gravitational effect the model predicts rather than the dark matter tracks the galaxies, not the hot, X-ray-emitting gas. The researchers call this an early proof of concept that needs more study.
“Observations attributed to dark matter and dark energy likely originate from covarying coupling constants,” adds Professor Gupta, whose paper on the origin of dark matter and dark energy explores the idea.
“We predict that galaxies exist well beyond the distances the James Webb Space Telescope has reached”
Rajendra Gupta
— Adjunct Professor in uOttawa’s Department of Physics
More time for early galaxies to form
The model could also help explain why astronomers keep finding large, mature galaxies so early in cosmic history.
In the standard model, the Universe was about 300 million years old during cosmic dawn. Under CCC+TL, it would have been about 4.6 billion years old at the same observed redshift. That extra time gives galaxies longer to grow and develop. In the researchers’ calculations, early galaxies come out about 12 times larger in size and mass than the standard model predicts, as reported in Galaxies 13, 115.
“Impossible early galaxies become predictable galaxies,” Professor Gupta explains. “We predict that galaxies exist well beyond the distances the James Webb Space Telescope has reached.”
That prediction may soon be tested. The James Webb Space Telescope’s GLIMPSE program plans to search for galaxies at redshifts that may exceed 50. In the standard model, there may not be enough time for massive galaxies to form that early. CCC+TL has no such limit.
A model worth further study
“The success should encourage astronomers to take the new model seriously. It is challenging to understand and apply, but we believe it extends the physics of the Universe beyond ΛCDM limits,” concludes Professor Gupta.
The study, titled “A Big Bang Nucleosynthesis Consistency Test of the CCC+TL Cosmology”, was published inthe journal Universe.
Authorship: Rajendra P. Gupta and Nikolaos Samaras - DOI: 10.3390/universe12070193
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