Christopher King, Jan 11 1959 – March 15, 2023.

An outstanding mathematician and scholar, mentor to his students and colleagues, a friend of Imperial College London, and a devoted husband and father, Chris passed away on March 15th, 2023, after a short illness.

Educated at Trinity College Dublin (B.A. in Mathematics, B.A. in Physics), and Harvard University (Ph.D.), he held positions at Cornell University, Princeton University, and most recently at Northeastern University, Boston. He also held visiting research positions at Microsoft Research, TU Berlin, California Institute of Technology, Eidgenossische Technische Hochschule (ETH) Zurich, the Dublin Institute for Advanced Studies (Ireland), and The Hamilton Institute (Ireland). Chris was a fellow of the American Mathematical Society and most recently he was a Visiting Professor at the Dyson School of Design Engineering, Imperial College London, where he delivered lectures on queuing theory, and actively participated in our research programmes.

While primarily a mathematician of outstanding ability, Chris was also driven by a desire to search for mathematics in important problem domains. Working on problems that are important, in a rigorous manner, the ability to fearlessly embrace new ideas and technologies, and the ability to recognise and exploit cross-domain connectivity, were the very skills that characterised Chris as a researcher and teacher of the highest calibre. He made deep and meaningful contributions to Theoretical Physics (where he started his career), Probability Theory, Stability Theory, and application areas such as Computer Networking, Smart Cities, and the study of Distributed Ledgers. A lifelong Quaker, his commitment to equality of opportunity led him to serve, amongst other things, as an advisor and mentor to secondary school students in under-resourced Boston public schools, through Northeastern's Bridge to Calculus program, and perhaps also served as a catalyst for his recent collaboration with the Dyson School of Design Engineering.

We have lost a great friend and colleague. His was a light that shone bright in the fields of applied and pure mathematics, stochastic processes, and dynamic systems. He was humble, gentle, and brilliant, in equal measure. We will miss him terribly.

Obituary written by Professor Shorten, Dyson School of Design Engineering.