Gravitational waves

How do black holes merge and make gravitational waves? Maybe with a little help from their friends.

Two independent papers vanquish lingering doubts about LIGO’s historic discovery of gravitational waves.

Cosmologists have predicted the existence of an oscillating signal that could distinguish between cosmic inflation and alternative theories of the universe’s birth.

Mathematicians have disproved the strong cosmic censorship conjecture. Their work answers one of the most important questions in the study of general relativity and changes the way we think about space-time.

New observations of extreme astrophysical systems have “brutally and pitilessly murdered” attempts to replace Einstein’s general theory of relativity.

Gravitational waves have opened up new ways to test the properties of black holes — and Einstein’s theory of gravity along with them.

The core of a neutron star is such an extreme environment that physicists can’t agree on what happens inside. But a new space-based experiment — and a few more colliding neutron stars — should reveal whether neutrons themselves break down.

Newly discovered “standard sirens” provide an independent, clean way to measure how fast the universe is expanding.

Astronomers have for the first time matched a gravitational-wave signal to a kilonova’s burst of light, observations that will “go down in the history of astronomy.”