Mathematicians are raising a major challenge to one of modern cosmology’s most widely accepted explanations: the idea that dark energy is driving the accelerating expansion of the universe.

A study published in Proceedings of the Royal Society A presents mathematical findings that researchers at the University of California, Davis, say reveal a fundamental instability in the standard model of the expanding universe. Their calculations suggest that cosmic acceleration could emerge naturally from Einstein’s equations, potentially eliminating the need to invoke mysterious dark energy.