Our best model of the cosmos has a glaring mathematical problem, but we may have found an answer.

The cosmological constant, originally introduced by Einstein as a measure of vacuum energy density, has re-emerged as a central challenge in understanding the observed accelerated expansion of the ...

We know that the universe is getting bigger. And we know that the speed that the universe is getting bigger is also getting bigger. The standard assumption is that the acceleration rate is itself ...

Cosmological models with varying fundamental constants explore the possibility that quantities traditionally regarded as immutable—such as the speed of light (c), Newton’s gravitational constant (G) ...