He became interested in differential geometry; he edited Wilhelm Blaschke's second volume on the topic,[4] and both made an acclaimed contribution to the Jena DMV conference in September 1921.[5][6]
In October 1922[2][3] or 1923[1] he was appointed assistant professor at the University of Vienna. While there he became familiar with the work of Wilhelm Wirtinger on knot theory, and became closely connected to Hans Hahn and the Vienna Circle. Its 1929 manifesto lists one of Reidemeister's publications[7] in a bibliography of closely related authors.
Blaschke managed to get a promise about Reidemeister's reappointment, and in autumn 1934 he got the chair of Kurt Hensel at the University of Marburg. He stayed there, except for a visit to the Princeton Institute for Advanced Study in 1948–1950, until he got appointed to Göttingen University in 1955, where he stayed until his emeritation.[1][2][3]
Works
Reidemeister's interests were mainly in combinatorial group theory, combinatorial topology, geometric group theory, and the foundations of geometry. His works include Knoten und Gruppen (1926), Einführung in die kombinatorische Topologie (1932), and Knotentheorie (1932). He co-edited the journal Mathematische Annalen from 1947 until 1963.[9]
He was also a philosopher. His book "Das exakte Denken der Griechen" (1949) is not as well known as his mathematical work. In it he remarks that mathematical thought is "just the beginning of thought".
