John McKay (1939-2022)

It is with sadness that we learned of the death of John McKay, a distinguished member of CICMA and the CRM, on April 19 in Montreal. Obtaining a PhD (Computer Science) from the University of Edinburgh in 1971, he joined Concordia University in 1974, becoming a professor in the Department of Computer Science there in 1979. John McKay’s work revolved around the properties of finite groups, their representations and their symmetries. He has been at the origin of several of the most startling discoveries in mathematics of our time, and is world-renowned for launching two areas of mathematics by his observations and conjectures, one known as the McKay correspondence, and the other going under the fanciful name of “monstrous moonshine”, which aims to explain the relationship between the linear representations of the largest sporadic simple group, known as the monster, and the Fourier coefficients of Klein’s modular function j.

Among other achievements, he pioneered in the use of computers as a tool in algebra, both in the study of sporadic groups (he is the co-discoverer of two such groups) or in the explicit computation of Galois groups. He was also one of the principal actors in one of the feats of computational algebra of our time, the proof of the non-existence of a projective plane of order 10. He was elected a fellow of the Royal Society of Canada in 2000 and awarded the CRM-Fields-PIMS prize in 2003.