Hans Werner Ballmann (born 1951) is a German mathematician. His area of research is differential geometry with focus on geodesic flows, spaces of negative curvature as well as spectral theory of Dirac operators
He currently is a professor at the University of Bonn, and the managing director of the Max Planck Institute for Mathematics in Bonn, Germany, since 2007.[1] He is a member of the German Academy of Sciences Leopoldina since 2007,[2] and a member of the scientific committee of the Mathematical Research Institute of Oberwolfach since 2004.