Klaus Wilhelm Roggenkamp (24 December 1940 – 23 July 2021[1]) was a German mathematician, specializing in algebra.
His thesis Darstellungen endlicher Gruppen in Polynombereichen (Representations of finite groups in polynomial integral domains) was written under the supervision of Hermann Boerner.
[2] Roggenkamp and Leonard Lewy Scott collaborated on a long series of papers on the groups of units of integral group rings, dealing with problems connected with the "integral isomorphism problem", which was proposed by Graham Higman in his 1940 doctoral dissertation at the University of Oxford.
[4][5] In 1986 Roggenkamp and Scott proved their most famous theorem (published in 1987 in the Annals of Mathematics).
Their 1987 paper also established a very strong form of a conjecture made by Hans Zassenhaus.
Klaus Roggenkamp managed to clarify completely the structure of blocks of p-adic group rings with cyclic defect group, thus establishing an integral analogue of the celebrated theory of Brauer tree algebras.
Many applications are known and more are on the way, from equivalences between derived categories to the inverse problem of Galois theory.A new branch of representation theory is created by Klaus Roggenkamp’s most recent research on higher-dimensional orders.
[2]Roggenkamp was elected a member of the Akademie gemeinnütziger Wissenschaften zu Erfurt (Erfurt Academy of Useful Sciences) and was made an honorary member of Ovidius University of Constanța in Romania.