Three physicists have proposed a modification to Einstein’s general relativity that, if confirmed, could eliminate the singularity at the origin of the universe. By adding higher-curvature terms to ...

In October 2015, a young mathematician named Clemens Sämann was flying home to Austria from a conference in Turin, Italy, when he had a chance encounter. He found himself seated beside Michael ...

General relativity describes gravity not as a force but as the curvature of spacetime produced by mass and energy. Matter tells spacetime how to curve, and this curved geometry guides the motion of ...

At its heart, general relativity is a geometric theory of gravitation in which spacetime is modelled as a four-dimensional Lorentzian manifold equipped with a metric tensor whose curvature encodes the ...