by Calvin C. Moore
I first “met” Kap mathematically when I was a graduate student at Harvard working in functional analysis and read and studied his striking 1951 papers on \( \mathrm{C}^* \)-algebras in which he defined and explored the properties of what he called CCR and GCR algebras. His algebraic insight into these objects arising in analysis turned out to be of seminal importance and indeed were years ahead of their time. I also read about what was by then called the Kaplansky density theorem for von Neumann algebras dating from 1952 and studied his wonderful 1948 paper on groups with representations of bounded degree and its connection with polynomial identities.
I was eager to meet this algebraist whose work had been so influential in my own studies in a very different field, and I had that opportunity when I had a postdoctoral appointment at Chicago in 1960–61. However, I soon left Chicago for Berkeley, and it was many years before our paths crossed again. When we were planning a full year program at the Mathematical Sciences Research Institute (MSRI) in 1983–84 on the topic of infinite dimensional Lie algebras, Kap’s broad and deep insight and understanding in algebra led us to select him as the chair of the program committee. We also recognized that his subtle and effective diplomatic skills would be essential ingredients in making this program the great success that it was.
Almost at the same time, the Board of Trustees of MSRI selected Kap to succeed Shiing-Shen Chern as director of MSRI in 1984. We served together at MSRI, he as director and I continuing as deputy director for a year before I left MSRI for an administrative post in the University of California. It was a wonderful learning and teaching experience for both of us. I learned much from Kap’s wisdom and experience, and I in turn tried to convey to him what I knew about MSRI operations. I subsequently watched more from a distance, and it was clear that MSRI grew and prospered under his eight years of excellent leadership as director. He also maintained a lively research program while serving as director and for many years after stepping down. We all miss this generous and wise man of many talents.
