The 100th anniversary edition of the Journal of the London Mathematical Society (JLMS ) includes an article reviewing the seminal 1989 work of Jeremy Rickard, Professor of Mathematics. To commemorate its first publication in January 1926, this flagship journal has been publishing a series of review papers summarising its major contributions over the years, including the work of mathematicians such as Hardy, Littlewood, Coxeter, Besicovitch, Erdös, Tutte, Roth and former Bristol Head of Department Hans Heilbronn.
The review of Professor Rickard’s foundational work developing Morita theory describes how his research “marked the beginning of an exciting development that continues to give new insights” and explains how “Rickard's work continues to inspire new developments far beyond its origins in representation theory”.
According to MathSciNet, the paper is the second most highly cited paper in the history of the journal. Professor Tim Burness, Head of the Institute of Pure Mathematics, congratulated Professor Rickard on this achievement, saying "Jeremy's landmark paper in JLMS is without doubt one of the most influential research articles to appear in the long and distinguished history of this journal; my colleagues and I are proud to see Jeremy's remarkable achievements recognised in this way."
Morita theory refers to a concept in advanced mathematics (specifically algebra) that says two different structures can look completely different on the surface, but they share the exact same "universe" of properties and behaviours. In maths, some structures are incredibly messy and difficult to work with. If a mathematician discovers that a messy structure is "Morita equivalent" to a much simpler, well-understood structure, they can translate the difficult problem into the simple language, solve it there, and translate the answer back. It is a powerful way to build bridges between seemingly unrelated mathematical worlds.