A new study led by physicist Rajendra Gupta suggests that dark matter and dark energy may not exist, attributing their effects to weakening fundamental forces as the universe expands. This theory uses a single equation to explain cosmic phenomena from galaxy rotations to the universe's expansion. Published in the journal Galaxies, it could reshape understandings of cosmic evolution.
For decades, dark matter and dark energy have been invoked to explain much of the universe's behavior, comprising most of its mass and driving its acceleration. However, Rajendra Gupta, an adjunct professor in the Department of Physics at the University of Ottawa, challenges this in his latest research. He proposes that these mysterious components are illusions arising from the gradual weakening of fundamental forces like gravity over cosmic time and space.
"The universe's forces actually get weaker on the average as it expands," Gupta explains. This weakening mimics dark energy's push at large scales, while variations in bound regions create extra gravity resembling dark matter at galactic and cluster levels. The model introduces a parameter, α, derived from evolving coupling constants that define force strengths. At cosmological scales beyond 600 million light years, α is constant; locally in galaxies, it varies with matter distribution—stronger in sparse areas, weaker in dense ones—explaining why outer stars orbit faster than expected without unseen halos.
Gupta's approach unifies explanations for diverse observations, including galaxy rotation, clustering, and light bending around massive objects. "There are two very different phenomena needed to be explained by dark matter and dark energy... Ours is the only one that explains them with the same equation, and without needing dark matter or dark energy," he states. It also addresses early universe puzzles, such as rapid galaxy and black hole formation post-Big Bang, by stretching the cosmic timeline to nearly double the standard age, allowing natural development without exotic particles.
The study, titled "Testing CCC+TL Cosmology with Galaxy Rotation Curves," appears in Galaxies (2025, 13(5):108). Gupta notes this could render the costly search for dark matter particles unnecessary, as even if found, they would account for only about six times ordinary matter's mass. "Sometimes, the simplest explanation is the best one. Maybe the Universe's biggest secrets are just tricks played by the evolving constants of nature," he concludes.