Riemann surfaces, Teichmüller theory and harmonic maps

  • Lecturer: Enno Keßler and Ruijun Wu
  • Date: Friday 09:30 - 11:00
  • Room: MPI MiS, A3 02
  • Target audience: MSc students, PhD students, Postdocs
  • Language: English
  • Keywords: Riemann surfaces, Teichmüller space, harmonic maps
  • Prerequisites: basic differential geometry


A Riemannian metric on an oriented surface, i.e. a two-dimensional oriented real manifold, turns the surface into a one-dimensional complex manifold. Teichmüller space is a differential geometric approach to the classification of complex structures on the surface. Due to its invariances, namely conformal and diffeomorphism invariance the action functional of harmonic maps on surfaces serves as a tool to study Teichmüller space. After a brief introduction to Riemann surfaces we want to use the theory of harmonic maps to prove

  •  the uniformization theorem: Every Riemann surface is the quotient of one of the three simply connected Riemann surfaces - Riemann sphere, the complex plane or the complex upper half plane.
  • Teichmüller theorem: The Teichmüller space is diffeomorphic to the space of holomorphic quadratic differentials on a given Riemann surface.

Here we will mostly follow the book "Compact Riemann surfaces" by Jürgen Jost. Depending on time and interest of the audience, we want to treat the Weil-Peterson geometry of Teichmüller space or give an outlook to the case of super Riemann surfaces.

Regular Lectures (Winter 2017/2018)

15.10.2018, 13:53