It was with great regret and sense of loss for the world of science that we received the news of the death of Prof. János Aczél – the outstanding mathematician, specialist in functional equations and honorary doctor of the University of Silesia in Katowice.
Prof. J. Aczél was affiliated with the universities in Budapest, Cologne, Florida and Waterloo (Canada) where he initiated research on functional equations in several variables. He was a member of the Royal Society of Canada (1971), foreign member of the Hungarian Academy of Sciences (1990) and Hamburg Mathematical Society, the oldest mathematical society in the world (2008).
In 1996 he obtained a honorary doctorate degree of the University of Silesia. He was also a honorary doctor of Technische Universität Karlsruhe (Germany, 1990) and Karl Franzens Universität in Graz (Austria, 1995).
Prof. János Aczél was the founder, chief editor and later honorary editor of the journal „Aequationes Mathematicae”, member of editorial boards of international mathematical journals, initiator and chair of the scientific committee of annual International Symposia on Functional Equations. He was the author of almost 300 papers on functional equations and several fundamental monographs. He closely cooperated with the Polish circle of functional equation specialists, and he was one of the most cited authors by Silesian mathematicians. His collaborators included mathematicians from the University of Silesia (joint publications with R. Ger, M. Kuczma and E. Siwek).
Prof. János Aczél died on 1 January 2020. The funeral will be held on 26 January 2020 at the cemetery in Ottawa (Canada), and he will be officially remembered during the event at the University of Waterloo on 17 April 2020.