Cosmology

The largest-ever 3D map of the cosmos hints that the dark energy that’s fueling the universe’s expansion may be weakening. One community of theoretical physicists expected as much.

A long-awaited study of the cosmic expansion rate suggests that when it comes to the Hubble tension, cosmologists are still missing something.

Physicists and cosmologists will have a new probe of primordial processes when Europe launches the Laser Interferometer Space Antenna (LISA) next decade.

A generation of physicists has referred to the dark energy that permeates the universe as “the cosmological constant.” Now the largest map of the cosmos to date hints that this mysterious energy has been changing over billions of years.

By mapping the largest structures in the universe in X-rays, cosmologists have found striking agreement with their standard theoretical model of how the universe evolves.

A controversial technique has produced detailed maps of the magnetic fields in colossal galaxy clusters. If confirmed, the approach could be used to reveal where cosmic magnetic fields come from.

An idea derived from string theory suggests that dark matter is hiding in a (relatively) large extra dimension. The theory makes testable predictions that physicists are investigating now.

As measurements of distant stars and galaxies become more precise, cosmologists are struggling to make sense of sparring values.

From the smallest scales to the largest, the physical world provided no shortage of surprises this year.