出典:Wikipedia
出典:『Wikipedia』 (2011/05/01 08:11 UTC 版)
Teleparallelism (also called distant parallelism and teleparallel gravity), was an attempt by Einstein to unify electromagnetism and gravity. The idea is to use a geometry with a pseudo-Riemannian metric of signature (3,1), vanishing curvature, and non-vanishing torsion, and to use tetrads, rather than the metric, as basic variables.