Donald G. Higman should not be confused with Graham Higman.
Donald G. Higman (September 20, 1928 in Vancouver – February 13, 2006) was an American mathematician known for his discovery, in collaboration with Charles C. Sims, of the Higman–Sims group.[1]
Higman did his undergraduate studies at the University of British Columbia,[1] and received his Ph.D. in 1952 from the University of Illinois Urbana-Champaign under Reinhold Baer. He served on the faculty of mathematics at the University of Michigan from 1956 to 1998.[1]
His work on homological aspects of group representation theory established the concept of a relatively-projective module and explained its role in the theory of module decompositions. He developed a characterization of rank-2 permutation groups, and a theory of rank-3 permutation groups; several of the later-discovered sporadic simple groups were of this type, including the Higman–Sims group which he and Sims constructed in 1967.[1]