After completing his doctorate in mathematics at Princeton, Halperin took a faculty position at Queen's University beginning in 1939. Halperin enlisted with the Canadian Army in 1942, serving until 1945 in Ottawa. Under the Royal Canadian Artillery, Halperin assisted with the Canadian Armament Research and Development Establishment (CARDE).[2] He then returned to Queen's.[3]
Arrest and release
In February 1946, Halperin was arrested and accused of espionage in Canada, in connection with the defection of Igor Gouzenko, a Sovietcipher clerk, which occurred in Ottawa in September 1945.[4] Gouzenko's defection and subsequent investigation showed that the Soviet Union was carrying on large-scale spying in Canada and the United States, including nuclear weapons espionage.
After some arduous questioning and confinement lasting several weeks, under a Royal Commission appointed by Justice Minister Louis St-Laurent, followed by a trial in early 1947, Halperin was eventually cleared and freed. He resumed teaching at Queen's, but not until 1948, following more legal hurdles which were raised by Queen's University leadership. Queen's Principal Robert Charles Wallace advocated his return.[5]
Later career
Following von Neumann's death in 1957, Halperin completed two of his unfinished papers, leaving them under von Neumann's name alone.[6]
Halperin taught at Queen's until 1966, earning tenure as a full professor. He then moved to the University of Toronto until his retirement in 1976, by which time he had authored more than 100 academic papers.
In 1980, the Israel Halperin Prize was set up by the Canadian Annual Symposium on Operator Theory and Operator Algebras to be awarded to a member of the Canadian mathematical community who has recently obtained a doctorate and has made contributions to operator theory or operator algebras, in honor of Halperin.
Halperin was awarded an honorary doctorate of laws from Queen's in 1989, and was made a Member of the Order of Canada, both for his humanitarian work.[7]
