William Feller

Infobox Scientist
box_width = 300px
name = Willy Feller

---

image_size = 300px
caption = Vilim "Willy" Feller (1906-1970)
birth_date = July 7 1906
birth_place = Zagreb, Croatia
death_date = January 14 1970
death_place = New York, USA
residence =
citizenship = American
nationality = Croatian
ethnicity = Croatian-Austrian-Polish-Jewish
fields = Mathematician
workplaces = University of Kiel
University of Copenhagen
University of Stockholm
University of Lund
Brown University
Cornell University
Princeton University
alma_mater = University of Zagreb
University of Göttingen
doctoral_advisor = Richard Courant
academic_advisors =
doctoral_students = George Forsythe
Lawrence Shepp
notable_students =
known_for = Feller process
Feller's coin-tossing constants
Feller-continuous process
Proof by intimidation
Feller transition function
Feller semigroup
Feller's property
Feller Brownian motions
Feller's test for explosions
Lindeberg-Feller condition
Feller operator
Feller potential
Feller measures
Krein-Feller differential operators
Kolmogorov-Feller equation
author_abbrev_bot =
author_abbrev_zoo =
influences = Stanko Vlögel
influenced =
awards = National Medal of Science (1969)
religion = Roman Catholic


footnotes =

William (Vilim) Feller "né" Vilibald Srećko Feller (July 7 1906 – January 14 1970), was a Croatian-American mathematician specializing in probability theory.

Early life and education

Feller was born in Zagreb to Ida Oemichen-Perc, a Croatian-Austrian Catholic, and Eugene Victor Feller, who was born to a Polish Jew named David Feller and an Austrian Catholic named Elsa Holzer. [ [http://www.croatianhistory.net/etf/feller.html#eugen William Feller's Origins] ] Eugen was a famous chemist and created "Elsa fluid" named after his mother. According to Gian-Carlo Rota, Feller's father's surname was a "Slavic tongue twister", which William changed at the age of twenty [cite book
last = Rota
first = Gian-Carlo
authorlink = Gian-Carlo Rota
year = 1996
title = Indiscrete Thoughts
publisher = Birkhäuser
id = ISBN 0-8176-3866-0] —but as can be seen, this claim was false. His christened name, Vilibald, was chosen by his Roman Catholic mother for the saint day of his birthday. [MacTutor Biography|id=Feller|title=William Feller] In his school documentation, the small municipality of Donja Stubica in Zagorje is mentioned. This is the birthplace of his father, who was an apothecary and owner of a company producing hygienic utensils and cosmetics.

William finished his elementary and middle education in Zagreb, as well as two years of his math study. From 1925, he continued his study in Göttingen, Germany where he gained the doctoral degree in 1926under the supervision of Richard Courant, with his work "Über algebraisch rektifizierbare transzendente Kurven".

Work

Feller held a docent position at the University of Kiel beginning in 1928. Because he refused to sign a Nazi oath, [cite web
title=Biography of William Feller
work=History of William Feller
url=http://www.croatianhistory.net/etf/feller.html#scandinavia
accessdate=2006-06-27] he fled the Nazis and went to Copenhagen, Denmark in 1933. He also lectured in Sweden (Stockholm and Lund). Finally, in 1939 he arrived in the U.S. where he became a citizen in 1944 and was on the faculty at Brown and Cornell. In 1950 he became a professor at Princeton University.

The works of Feller are contained in 104 papers and two books on a variety of topics such as mathematical analysis, theory of measurement, functional analysis, geometry, and differential equations.

He was among the foremost probabilists outside of Russia. In the middle of the 20th century, probability was not generally viewed as a fruitful area of research in mathematics except in Russia, where Kolmogorov and others were influential. Feller contributed to the study of the relationship between Markov chains and differential equations. He wrote a two-volume treatise on probability that has since been universally regarded as one of the most important treatments of that subject.

Results

Numerous topics relating to probability are named after him, including the Feller process, Feller's explosion test, Feller-Brown movement, Feller property and Lindberg-Feller theorem. Books written by him and published as textbooks are considered invaluable in the popularisation of the theory of probability and among the best written during the 20th century.

Despite the fact that he spent the better part of his life out of Croatia where he was born and grew up, and where he started his education, he was in touch with his relatives there, and with his colleagues at University of Zagreb, whom he sometimes visited and lectured. He received numerous awards and was an honoured member of numerous educational institutions (in Boston, Zagreb, London, Copenhagen).

Feller initiated the publication of the now well-known review journal "Mathematical Reviews".

References

External links

*
* [http://jagor.srce.hr/zuh/velikani/vel_int.htm Croatian Giants of Science - in Croatian]
*MacTutor Biography|id=Feller|title=William Feller
* [http://libweb.princeton.edu/libraries/firestone/rbsc/finding_aids/mathoral/pmcxrota.htm "Fine Hall in its golden age: Remembrances of Princeton in the early fifties" by Gian-Carlo Rota.] Contains a section on Feller at Princeton.
* [http://www.croatianhistory.net/gif/felln.jpgFeller Matriculation Form giving personal details]