Riemannian manifold | Metric system | United States Metric Board | metric system | Alex Metric | U.S. Metric Association | The Metric Marvels | Performance metric | Metric signature | Metric expansion of space | metric expansion of space | Kerr metric | Kantowski-Sachs metric | Gödel metric | Friedmann–Lemaître–Robertson–Walker metric | Fisher information metric |
The classic solution of the Einstein field equations that describes a homogeneous and isotropic universe is called the Friedmann–Lemaître–Robertson–Walker metric, or FLRW, after Friedmann, Georges Lemaître, Howard Percy Robertson and Arthur Geoffrey Walker, who worked on the problem in 1920's and 30's independently of Friedmann.
where is the spatial scalar curvature computed with respect to the Riemannian metric and is the extrinsic curvature,