Ky Fan (樊𰋀, , September 19, 1914 – March 22, 2010) was a Chinese-born American

mathematician A mathematician is someone who uses an extensive knowledge of mathematics in their work, typically to solve mathematical problems. Mathematicians are concerned with numbers, data, quantity, structure, space, models, and change. History On ...

. He was a professor of mathematics at the

University of California, Santa Barbara The University of California, Santa Barbara (UC Santa Barbara or UCSB) is a public land-grant research university in Santa Barbara, California with 23,196 undergraduates and 2,983 graduate students enrolled in 2021–2022. It is part of the U ...

Biography

Fan was born in

Hangzhou Hangzhou ( or , ; , , Standard Mandarin pronunciation: ), also romanized as Hangchow, is the capital and most populous city of Zhejiang, China. It is located in the northwestern part of the province, sitting at the head of Hangzhou Bay, whic ...

, the capital of Zhejiang Province, China. His father, named Fan Qi (樊琦, 1879—1947), served in the district courts of Jinhua and

Wenzhou Wenzhou (pronounced ; Wenzhounese: Yuziou �y33–11 tɕiɤu33–32 ), historically known as Wenchow is a prefecture-level city in southeastern Zhejiang province in the People's Republic of China. Wenzhou is located at the extreme south east ...

. Ky Fan went to Jinhua with his father when he was eight years old and studied at several middle schools in Zhejiang, including the Jinhua High School (currently Jinhua No.1 Middle School), Hangzhou Zongwen High School (currently Hangzhou No.10 Middle School), and Wenzhou High School. Fan obtained his secondary diploma from the Jinhua High School. Fan enrolled into Peking University Department of Mathematics in 1932, and received his B.S. degree from Peking University in 1936. Initially Fan wanted to study

engineering Engineering is the use of scientific principles to design and build machines, structures, and other items, including bridges, tunnels, roads, vehicles, and buildings. The discipline of engineering encompasses a broad range of more speciali ...

, but eventually shifted to mathematics, largely because of the influence of his uncle Feng Zuxun ( 冯祖荀, 1880–1940; b. Hangzhou, d. Beijing), who was a mathematician in China and the then Chair of the Department of Mathematics of Peking University. After graduation, Fan became a

teaching assistant A teaching assistant or teacher's aide (TA) or education assistant (EA) or team teacher (TT) is an individual who assists a teacher with instructional responsibilities. TAs include ''graduate teaching assistants'' (GTAs), who are graduate stude ...

in the department. Fan went to

France France (), officially the French Republic ( ), is a country primarily located in Western Europe. It also comprises of overseas regions and territories in the Americas and the Atlantic, Pacific and Indian Oceans. Its metropolitan area ...

in 1939 and received his D.Sc. degree from the

University of Paris , image_name = Coat of arms of the University of Paris.svg , image_size = 150px , caption = Coat of Arms , latin_name = Universitas magistrorum et scholarium Parisiensis , motto = ''Hic et ubique terrarum'' (Latin) , mottoeng = Here and a ...

in 1941. Fan's doctoral advisor was M.R.Fréchet. Fan was a

research fellow A research fellow is an academic research position at a university or a similar research institution, usually for academic staff or faculty members. A research fellow may act either as an independent investigator or under the supervision of a pr ...

at the

French National Centre for Scientific Research The French National Centre for Scientific Research (french: link=no, Centre national de la recherche scientifique, CNRS) is the French state research organisation and is the largest fundamental science agency in Europe. In 2016, it employed 31,63 ...

(CNRS). During his secondary school and college time, Fan said he "hated

English English usually refers to: * English language * English people English may also refer to: Peoples, culture, and language * ''English'', an adjective for something of, from, or related to England ** English national ide ...

". That was an important reason for him to choose mathematics, with less English but full of equations, and go to Paris. Fan was a member of the

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

Princeton, New Jersey Princeton is a municipality with a borough form of government in Mercer County, in the U.S. state of New Jersey. It was established on January 1, 2013, through the consolidation of the Borough of Princeton and Princeton Township, both of whi ...

from 1945 to 1947. In 1947, Fan joined the mathematical faculty of the

University of Notre Dame The University of Notre Dame du Lac, known simply as Notre Dame ( ) or ND, is a private Catholic university, Catholic research university in Notre Dame, Indiana, outside the city of South Bend, Indiana, South Bend. French priest Edward Sorin fo ...

, where he was an

assistant professor Assistant Professor is an academic rank just below the rank of an associate professor used in universities or colleges, mainly in the United States and Canada. Overview This position is generally taken after earning a doctoral degree A docto ...

at the beginning, and later promoted to associate professor and full

professor Professor (commonly abbreviated as Prof.) is an academic rank at universities and other post-secondary education and research institutions in most countries. Literally, ''professor'' derives from Latin as a "person who professes". Professors ...

. In 1960, Fan also held a position at

Wayne State University Wayne State University (WSU) is a public research university in Detroit, Michigan. It is Michigan's third-largest university. Founded in 1868, Wayne State consists of 13 schools and colleges offering approximately 350 programs to nearly 25,000 ...

Detroit Detroit ( , ; , ) is the largest city in the U.S. state of Michigan. It is also the largest U.S. city on the United States–Canada border, and the seat of government of Wayne County. The City of Detroit had a population of 639,111 at t ...

for about one year, but immediately went to

Northwestern University Northwestern University is a private research university in Evanston, Illinois. Founded in 1851, Northwestern is the oldest chartered university in Illinois and is ranked among the most prestigious academic institutions in the world. Charte ...

near

Chicago (''City in a Garden''); I Will , image_map = , map_caption = Interactive Map of Chicago , coordinates = , coordinates_footnotes = , subdivision_type = Country , subdivision_name ...

. In 1965, Fan became a professor of mathematics at UCSB. Fan was known for being an extremely strict professor.Memory of my teacher -- Ky Fan
by Chuan-Kuan Yuan (袁传宽, American computer scientist) Fan was elected an Academician of the Academia Sinica (

Taipei Taipei (), officially Taipei City, is the capital and a special municipality of the Republic of China (Taiwan). Located in Northern Taiwan, Taipei City is an enclave of the municipality of New Taipei City that sits about southwest of the ...

Taiwan Taiwan, officially the Republic of China (ROC), is a country in East Asia, at the junction of the East and South China Seas in the northwestern Pacific Ocean, with the People's Republic of China (PRC) to the northwest, Japan to the nort ...

) in 1964. He served as the director of the Institute of Mathematics there from 1978 to 1984. In 1999, Fan and his wife Yan Youfen (燕又芬) donated one million

US dollars The United States dollar (symbol: $; code: USD; also abbreviated US$ or U.S. Dollar, to distinguish it from other dollar-denominated currencies; referred to as the dollar, U.S. dollar, American dollar, or colloquially buck) is the official ...

to the

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, ...

, to set up the ''Ky and Yu-Fen Fan Endowment''. Fan had 23 graduate students. He died in Santa Barbara in March 2010. His given name 𰋀 ( Zh cj-gviw

) is a rare variant of the character 畿.

Academic career

Fan was a student and collaborator of M. Fréchet and was also influenced by

John von Neumann John von Neumann (; hu, Neumann János Lajos, ; December 28, 1903 – February 8, 1957) was a Hungarian-American mathematician, physicist, computer scientist, engineer and polymath. He was regarded as having perhaps the widest cove ...

and Hermann Weyl. The author of approximately 130 papers, Fan made fundamental contributions to operator and matrix theory, convex analysis and inequalities, linear and nonlinear programming, topology and fixed point theory, and topological groups. His work in fixed point theory, in addition to influencing nonlinear functional analysis, has found wide application in mathematical economics and game theory, potential theory, calculus of variations, and differential equations. The following are named after him: * Ky Fan norms * Ky Fan inequality * Ky Fan inequality (game theory) * Ky Fan lemma

Publications

*''Sur quelques notions fondamentales de l'analyse générale'', 1941 *''Introduction à la topologie combinatoire'', co-author with M.R.Fréchet, first published in 1946, later translated into English and

Spanish Spanish might refer to: * Items from or related to Spain: **Spaniards are a nation and ethnic group indigenous to Spain **Spanish language, spoken in Spain and many Latin American countries **Spanish cuisine Other places * Spanish, Ontario, Can ...

.
Invitation to combinatorial topology
2003 *''Fonctions définies-positives et les fonctions complètement monotones; leurs applications au calcul des probabilités et à la théorie des espaces distanciés'', 1950

References

External links

*
Obituary of Ky Fan
by Bor-Luh Lin in the

Notices of the American Mathematical Society ''Notices of the American Mathematical Society'' is the membership journal of the American Mathematical Society (AMS), published monthly except for the combined June/July issue. The first volume appeared in 1953. Each issue of the magazine since ...

.
Tales of Dr. Fan
by Dennis Wildfogel. {{DEFAULTSORT:Fan, Ky 1914 births 2010 deaths 20th-century American mathematicians Chinese emigrants to the United States Educators from Hangzhou Institute for Advanced Study visiting scholars Mathematicians from Zhejiang Members of Academia Sinica Northwestern University faculty National University of Peking alumni Peking University faculty Scientists from Hangzhou University of California, Santa Barbara faculty University of Notre Dame faculty University of Paris alumni Wayne State University faculty Chinese expatriates in France