The accelerating expansion of the universe is usually explained by an invisible force known as dark energy. But a new study ...

A variation on the theory of quantum gravity — the unification of quantum mechanics and Einstein's general relativity — could help solve one of the biggest puzzles in cosmology, new research suggests.

Quantum theory and Einstein's theory of general relativity are two of the greatest successes in modern physics. Each works ...

There’s still a lot we don’t know about dark matter, or the “missing” mass supposedly constituting around 85% of the universe. Physicists have good reason to believe it’s out there. New research ...