Gerhard Hessenberg

Gerhard Hessenberg ( born August 16, 1874 in Frankfurt am Main, † November 16, 1925 in Berlin) was a German mathematician.

Life and work

Gerhard Hessenberg studied in Strasbourg and Berlin. Promotion 1899. Habilitation in 1901 at the Technical University Berlin. In 1907 he became professor at the Agricultural Academy in Bonn, 1910 at the Technical University of Wroclaw. 1919 he was appointed to the University of Tübingen.

Hessenberg employed in his work, etc. with differential geometry ( geodesics ) and basic questions of geometry. He developed, inter alia, an axiom system of elliptic geometry. For the synthetic study of projective planes and spaces of 1905 proved by him set is important that also applies to the set of Desargues in each plane in which the projective incidence axioms and the set of Pappus apply. It is named in his honor set of Hessenberg.

He was also known for his 1906 published treatise on set theory, in which he fully the - proved statement that is true for all infinite cardinal numbers - also known as a set of Hessenberg. Although this paper must be viewed from a mathematical point of view in much of as obsolete today, they still deserve According to Oliver Deiser the predicate " historically have been particularly valuable ."

Works (selection)

• G. Hessenberg: plane and spherical trigonometry. de Gruyter, Berlin (various editions).
• G. Hessenberg: Basic concepts of set theory. Proceedings of the Friesian School, New Edition, Vol 1, pp. 478 -706 ( in book form as a separate report published by Vandenhoeck and Ruprecht, Göttingen 1906).
• G. Hessenberg: Foundations of Geometry. de Gruyter, Berlin ² 1967. (EA 1930)
• G. Hessenberg: transcendence of e and π. A contribution to higher mathematics from elementary point of view. New York in 1965, unchanged reprint of the EA of 1912.
• G. Hessenberg: From the sense of the numbers. Tübingen / Leipzig 1922.