| Description |
After discussing the basic definitions of manifold theory, vector bundles and differential forms, the notion of a Riemannian manifold will be introduced. This is a manifold equipped with a Riemannian metric, i.e., a positive definite inner product on the tangent space at each point, depending smoothly on that point. The Riemannian metric allows the definition of length of a smooth curve. A curve that is locally of shortest length, is called a geodesic. In local coordinates, a geodesic may be descibed in terms of a second order ordinary differential equation. The geodesic equation is best described in terms of covariant differentiation, i.e., differentiation with respect to a so-called connection on the bundle of tangent spaces. More generally we will discuss the notion of connection on a vector bundle, the associated parallel transport, and the curvature tensor. A Riemannian metric gives rise to a uniquely defined connection, the so-called Levi-Civita connection. The associated notions of sectional curvature and scalar curvature will be discussed. The primary goal is to give a proof of the Gauss-Bonnet theorem for a compact Riemannian surface, which links the scalar curvature to the topology of the manifold. If time permits, another application of the theory will be given. |