An older universe could give unexpectedly mature early galaxies billions more years to grow, according to a model that also reproduces galaxy rotation without dark matter.

To explain how galaxies rotate, the standard model of the universe relies on dark matter, an unseen source of gravity. A new paper published in Monthly Notices of the Royal Astronomical Society reports that an alternative model can reproduce the rotation curves of all 175 galaxies in the SPARC database without dark matter. These curves show how orbital speeds change with distance from a galaxy’s center, giving researchers a way to test the gravity their model predicts.

The galaxy study is part of a series of tests conducted during 2025 and 2026 by Rajendra Gupta, an adjunct professor in the University of Ottawa’s Department of Physics, and postdoctoral researcher Dr. Nikolaos Samaras. They compared important astronomical observations with predictions from CCC+TL, a model that puts the universe’s age at 26.7 billion years and proposes that neither dark matter nor dark energy is needed.