Coframe
In mathematics, a coframe or coframe field on a smooth manifold is a system of one-forms or covectors which form a basis of the cotangent bundle at every point. In the exterior algebra of, one has a natural map from, given by. If is dimensional a coframe is given by a section of such that. The inverse image under of the complement of the zero section of forms a principal bundle over, which is called the coframe bundle.
