Cosmology

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

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.

Ripples in space-time have been detected a century after Einstein predicted them, launching a new era in astronomy.

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.

The physicist James Bullock explains how a complicated “dark sector” of interacting particles may illuminate some puzzling observations of the centers of galaxies.

Explore the deepest mysteries at the frontier of fundamental physics, and the most promising ideas put forth to solve them.

Scientists haven’t tested the Big Bang’s light for a revealing shift in 25 years. A new experiment aims to change that.

Three physicists have proposed a new solution to one of the deepest mysteries in particle physics: why the Higgs boson has such a tiny mass.

Physicists are beginning to unravel the mysteries of ultrahigh-energy cosmic rays, particles accelerated by the most powerful forces in the universe.