This set of selected papers of Klingenberg covers some of the important mathematical aspects of Riemannian Geometry, Closed Geodesics, Geometric Algebra, Classical Differential Geometry and Foundations of Geometry of Klingenberg. Of significance were his contributions to Riemannian Geometry in the Large which opened a new area in Global Riemannian Geometry. He also introduced the Hilbert manifold of closed curves of class H¹ on a Riemannian manifold. In connection with his work in closed geodesics, he became interested in the properties of the geodesic flow. Classical results from dynamical systems became useful tools for the study of closed geodesics. He was also credited for drawing closer together Riemannian Geometry and Hamiltonian systems, which had developed separately since the time of H Poincaré.

Besides publishing research papers, Klingenberg also wrote a dozen books and lecture notes, among which is the important reference work “Riemannsche Geometrie im Groβen”.

• Classical Differential Geometry:
  • Closed Curves on S² with Bounded Winding Number
• Foundations of Geometry:
  • Beziehungen Zwischen Einigen Affinen Schlieβungssätzen
  • Projektive Geometrien mit Homomorphismus
• Geometric Algebra:
  • Über die Arfsche Invariante Quadratischer Formen Mod 2
  • Projektive Geometrie und Lineare Algebra über Verallgemeinerten Bewertungsringen
  • Symplectic Groups Over Local Rings
• Riemannian Geomerty:
  • Contributions to Riemannian Geometry in the Large
  • On Compact Kaehlerian Manifolds with Positive Holomorphic Curvature
• Closed Geodesics:
  • The Space of Closed Curves on a Projective Space
  • Der Indexsatz für Geschlossene Geodätische
  • Über die Existenz Unendlich Vieler Geschlossener Geodätischer
  • Homology Generated by Iterated Closed Geodesics
  • and other papers