or diffeomorphic to R 2 {\displaystyle \mathbb {R} ^{2}} , by work of Cohn-Vossen from 1935. In three dimensions the conjecture holds due to a noncompact...

Stefan Cohn-Vossen had originally formulated and proved the theorem in the case of two-dimensional manifolds, and Victor Toponogov had extended Cohn-Vossen's...

David Christiani Christopher Clavius Stephan Cohn-Vossen Paul Cohn Armin B. Cremers Peter Crüger Richard Dedekind Herbert von Denffer Christopher Deninger...

geometry have been proposed (see for example Coxeter 2003, Hilbert & Cohn-Vossen 1999, Greenberg 1980). These axioms are based on Whitehead, "The Axioms...

Natick, Massachusetts: A K Peters. pp. 275–290. MR 1956254. Hilbert, D.; Cohn-Vossen, S. (1952). Geometry and the Imagination. New York, N. Y.: Chelsea Publishing...

W. Blaschke, Richard Courant, Springer-Verlag, 2013, ISBN 3642498485, S. 58. Glaeser-Stachel-Odehnal: p. 147 D. Hilbert, S. Cohn-Vossen:Geometry and the...

The simplest of these shapes is the tetrahedron... Hilbert, David; Cohn-Vossen, Stephan (1999). Geometry and the Imagination. American Mathematical...

between two points cannot have length greater than δ. Rigidity. In 1927 Cohn-Vossen proved that two ovaloids – closed surfaces with positive Gaussian curvature...

Philosophy. London. doi:10.4324/9780415249126-S036-1. ISBN 9780415250696. Vossen, Bas Van Der (2017). "Libertarianism". Oxford Research Encyclopedia of Politics...

octonions, A K Peters, Ltd., pp. 34, ISBN 978-1-56881-134-5 Hilbert, David; Cohn-Vossen, S. (1999), Geometry and the imagination, AMS Bookstore, p. 147, ISBN 978-0-8218-1998-2...