If a point of Teichmüller space is represented by a Riemann surface
R, then the cotangent space at that point can be identified with the space of
quadratic differentials at
R. Since the Riemann surface has a natural
hyperbolic metric, at least if it has negative
Euler characteristic, one can define a
Hermitian inner product on the space of quadratic differentials by integrating over the Riemann surface. This induces a Hermitian inner product on the tangent space to each point of Teichmüller space, and hence a Riemannian metric. ==Properties==