Dark matter

Cosmologists are using secondary signatures from the cosmic microwave background to map the universe’s hidden matter.

Big Freeze, Big Rip, Big Crunch, Bounce or vacuum decay? Steven Strogatz speaks with theoretical cosmologist Katie Mack about the five ways that scientists think the universe could come to an end.

Reports that the James Webb Space Telescope killed the reigning cosmological model turn out to have been exaggerated. But astronomers still have much to learn from distant galaxies glimpsed by Webb.

A growing catalog of huge but dim galaxies such as Dragonfly 44 is forcing astronomers to invent new theories of galactic evolution.

A recent gamma-ray burst known as the BOAT — “brightest of all time” — appears to have produced a high-energy particle that shouldn’t exist. For some, dark matter provides the explanation.

Physicists are devising clever new ways to exploit the extreme sensitivity of gravitational wave detectors like LIGO. But so far, they’ve seen no signs of exotica.

When astronomers tried to confirm a signal from the birth of the first stars after the Big Bang, they saw nothing.

Celia Escamilla-Rivera is combining large data sets with supercomputers to test general relativity against its little-known competitors.

A central pillar of cosmology — the universe is the same everywhere and in all directions — is surviving a storm of possible evidence against it.