Maurice Sion (17 October 1927,

Skopje Skopje ( , ; ; , sq-definite, Shkupi) is the capital and largest city of North Macedonia. It lies in the northern part of the country, in the Skopje Basin, Skopje Valley along the Vardar River, and is the political, economic, and cultura ...

– 17 April 2018,

Vancouver Vancouver is a major city in Western Canada, located in the Lower Mainland region of British Columbia. As the List of cities in British Columbia, most populous city in the province, the 2021 Canadian census recorded 662,248 people in the cit ...

) was an American and Canadian mathematician, specializing in

measure theory In mathematics, the concept of a measure is a generalization and formalization of geometrical measures (length, area, volume) and other common notions, such as magnitude (mathematics), magnitude, mass, and probability of events. These seemingl ...

and game theory. He is known for Sion's minimax theorem.

Biography

Sion received from

New York University New York University (NYU) is a private university, private research university in New York City, New York, United States. Chartered in 1831 by the New York State Legislature, NYU was founded in 1832 by Albert Gallatin as a Nondenominational ...

his B.A. in 1947 and his M.A. in 1948. He received from the

University of California, Berkeley The University of California, Berkeley (UC Berkeley, Berkeley, Cal, or California), is a Public university, public Land-grant university, land-grant research university in Berkeley, California, United States. Founded in 1868 and named after t ...

in 1951 his Ph.D. under the supervision of

Anthony Morse Anthony Perry Morse (21 August 1911 – 6 March 1984) was an American mathematician who worked in both analysis, especially measure theory, and in the foundations of mathematics. He is best known as the co-creator, together with John L. Kelle ...

with thesis ''On the existence of functions having given partial derivatives on Whitney's curve''. Sion was a member of the mathematics faculty at U.C. Berkeley until 1960, when he immigrated to Canada with his wife Emilie and his two children born in the U.S.A. (His two younger children were born in Canada.) From 1960 until he retired in 1989, Maurice Sion was a professor of mathematics at the

University of British Columbia The University of British Columbia (UBC) is a Public university, public research university with campuses near University of British Columbia Vancouver, Vancouver and University of British Columbia Okanagan, Kelowna, in British Columbia, Canada ...

. For two academic years from 1957 to 1959 and in the autumn of 1962 he was at the

Institute for Advanced Study The Institute for Advanced Study (IAS) is an independent center for theoretical research and intellectual inquiry located in Princeton, New Jersey. It has served as the academic home of internationally preeminent scholars, including Albert Ein ...

. He wrote several books on mathematics and served for many years as the head of the University of British Columbia's mathematics department. In 1957 he was the coauthor with Philip Wolfe of a paper with an example of a zero-sum game without a minimax value. Sion was an Invited Speaker at the

International Congress of Mathematicians The International Congress of Mathematicians (ICM) is the largest conference for the topic of mathematics. It meets once every four years, hosted by the International Mathematical Union (IMU). The Fields Medals, the IMU Abacus Medal (known before ...

(ICM) in 1970 in

Nice Nice ( ; ) is a city in and the prefecture of the Alpes-Maritimes department in France. The Nice agglomeration extends far beyond the administrative city limits, with a population of nearly one million American Mathematical Society The American Mathematical Society (AMS) is an association of professional mathematicians dedicated to the interests of mathematical research and scholarship, and serves the national and international community through its publications, meetings, ...

. Sion was fluent in Spanish, Italian, French, and English. He was predeceased by his youngest child. Upon his death he was survived by his widow, three children, and six grandchildren.

Selected publications

Articles

* * * with R. C. Willmott: *

Books

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References

{{DEFAULTSORT:Sion, Maurice 1927 births 2018 deaths People from Skopje New York University alumni University of California, Berkeley alumni Academic staff of the University of British Columbia American people of Sephardic-Jewish descent 20th-century American mathematicians 21st-century American mathematicians 20th-century Canadian mathematicians 21st-century Canadian mathematicians Mathematical analysts Measure theorists Fellows of the American Mathematical Society