Cosmology

Einstein’s equations describe three canonical configurations of space-time. Now one of these three — important in the study of quantum gravity — has been shown to be inherently unstable.

Physicists have proposed extra cosmic ingredients that could explain the faster-than-expected expansion of space.

In our mind’s eye, the universe seems to go on forever. But using geometry we can explore a variety of three-dimensional shapes that offer alternatives to “ordinary” infinite space.

The recent discovery of some of the first galaxies in the universe illuminates the darkest era in cosmic history.

A problem confronts cosmology: Two independent measurements of the universe’s expansion give incompatible answers. Now a third method, advanced by an astronomy pioneer, appears to bridge the divide.

A photograph of the infant cosmos reveals the precise amounts of dark matter and dark energy in the universe, leaving precious little room for argument.

Physicists saw a black hole for the first time, debated the expansion rate of the universe, pondered the origin of time and modeled the end of clouds.

A study challenged the evidence for the mysterious antigravitational force known as dark energy. Then cosmologists shot back.

Physicists have long searched for hypothesized dark matter particles called WIMPs. Now, focus may be shifting to the axion — an ultra-lightweight particle whose existence would solve two mysteries at once.