A new study casts doubt on the universe’s accelerating expansion, suggesting dark energy might be weakening over time.

The universe is expanding. That much is clearer. But it’s less clear whether this expansion is accelerating or slowing down.

There's always a touch of melancholy when a chapter that has absorbed years of work comes to an end. In the case of the ...

Scientists have many big questions to tackle about the universe, including how big it actually is. But even the proposed ...

UChicago physics Prof. Bonnie Fleming, who is also the chief research officer at Fermi National Accelerator Laboratory, is ...

"If our solar system is indeed moving this fast, we need to question fundamental assumptions about the large-scale structure ...

The "standard model" of cosmology, initially based on the Big Bang, the expansion of the universe, and the cosmic microwave background radiation, evolved into a more comprehensive "lambda-cold dark ...

Astronomers have assumed for decades that the Universe is expanding at the same rate in all directions. A new study based on data from ESA’s XMM-Newton, NASA’s Chandra and the German-led ROSAT X-ray ...

This is the light echo of the Big Bang, the first light that freely moved through the universe. This relic is crucial to our ...