Tangent bundleIn mathematics, the tangent bundle of a manifold is the union of all the tangent spaces at every point in the manifold.
Definition as directions of curvesSuppose is a manifold, and , where is an open subset of , and is the dimension of the manifold, in the chart ; furthermore suppose is the tangent space at a point in . Then the tangent bundle,
It is useful, in distinguishing between the tangent space and bundle, to consider their dimensions, n and 2n respectively. That is, the tangent bundle accounts for dimensions in the positions in the manifold as well as directions tangent to it.