Theoretical physics

The story of the universe’s birth — and evidence for string theory — could be found in triangles and myriad other shapes in the sky.

In the new, free-for-all era of dark matter research, the controversial idea that dark matter is concentrated in thin disks is being rescued from scientific oblivion.

The path from a revolutionary set of equations to the detection of gravitational waves was strewn with obstacles and controversy, explains the physicist Daniel Kennefick — and the struggle continues.

The physicist Subir Sachdev borrows tools from string theory to understand the puzzling behavior of high-temperature superconductors.

Bizarre quantum bonds connect distinct moments in time, suggesting that quantum links — not space-time — constitute the fundamental structure of the universe.

Two leading candidates for a “theory of everything,” long thought to be incompatible, may be two sides of the same coin.

The irreversibility of time may be a clue as to what makes up the universe’s dark matter.

If a theory can’t be tested, is it still science?

Nima Arkani-Hamed is championing a campaign to build the world’s largest particle collider, even as he pursues a new vision of the laws of nature.