Carl Einar Hille (28 June 1894 – 12 February 1980) was an American mathematics professor and scholar. Hille authored or coauthored twelve mathematical books and a number of mathematical papers.
Early life and education
Hille was born in
New York City
New York, often called New York City or NYC, is the most populous city in the United States. With a 2020 population of 8,804,190 distributed over , New York City is also the most densely populated major city in the Un ...
. His parents were both immigrants from Sweden who separated before his birth. His father, Carl August Heuman, was a civil engineer. He was brought up by his mother, Edla Eckman, who took the surname Hille. When Einar was two years old, he and his mother returned to
Stockholm. Hille spent the next 24 years of his life in Sweden, returning to the United States when he was 26 years old. Hille entered the
University of Stockholm
Stockholm University ( sv, Stockholms universitet) is a public research university in Stockholm, Sweden, founded as a college in 1878, with university status since 1960. With over 33,000 students at four different faculties: law, humanities, soci ...
in 1911. Hille was awarded his first degree in mathematics in 1913 and the equivalent of a master's degree in the following year. He received a Ph.D. from Stockholm in 1918 for a doctoral dissertation entitled ''Some Problems Concerning Spherical Harmonics''.
Career
In 1919 Hille was awarded the
Mittag-Leffler Prize and was given the right to teach at the University of Stockholm. He subsequently taught at
Harvard University
Harvard University is a private Ivy League research university in Cambridge, Massachusetts. Founded in 1636 as Harvard College and named for its first benefactor, the Puritan clergyman John Harvard, it is the oldest institution of high ...
,
Princeton University
Princeton University is a private research university in Princeton, New Jersey. Founded in 1746 in Elizabeth as the College of New Jersey, Princeton is the fourth-oldest institution of higher education in the United States and one of the ...
,
Stanford University and the
University of Chicago
The University of Chicago (UChicago, Chicago, U of C, or UChi) is a private university, private research university in Chicago, Illinois. Its main campus is located in Chicago's Hyde Park, Chicago, Hyde Park neighborhood. The University of Chic ...
. In 1933, he became an endowed professor on mathematics in the Graduate School of
Yale University
Yale University is a Private university, private research university in New Haven, Connecticut. Established in 1701 as the Collegiate School, it is the List of Colonial Colleges, third-oldest institution of higher education in the United Sta ...
, retiring in 1962.
Hille's main work was on
integral equation
In mathematics, integral equations are equations in which an unknown function appears under an integral sign. In mathematical notation, integral equations may thus be expressed as being of the form: f(x_1,x_2,x_3,...,x_n ; u(x_1,x_2,x_3,...,x_n) ...
s,
differential equation
In mathematics, a differential equation is an equation that relates one or more unknown functions and their derivatives. In applications, the functions generally represent physical quantities, the derivatives represent their rates of change, an ...
s,
special function
Special functions are particular mathematical functions that have more or less established names and notations due to their importance in mathematical analysis, functional analysis, geometry, physics, or other applications.
The term is defined b ...
s,
Dirichlet series
In mathematics, a Dirichlet series is any series of the form
\sum_^\infty \frac,
where ''s'' is complex, and a_n is a complex sequence. It is a special case of general Dirichlet series.
Dirichlet series play a variety of important roles in analy ...
and
Fourier series. Later in his career his interests turned more towards
functional analysis
Functional analysis is a branch of mathematical analysis, the core of which is formed by the study of vector spaces endowed with some kind of limit-related structure (e.g. inner product, norm, topology, etc.) and the linear functions defined o ...
. His name persists among others in the
Hille–Yosida theorem. Hille was a member of the
London Mathematical Society and the
Circolo Matematico di Palermo The Circolo Matematico di Palermo (Mathematical Circle of Palermo) is an Italian mathematical society, founded in Palermo by Sicilian geometer Giovanni B. Guccia in 1884. . Hille served as president of 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, ...
(1947–48) and was the Society's Colloquium lecturer in 1944. He received many honours including election to the
United States National Academy of Sciences
The National Academy of Sciences (NAS) is a United States nonprofit, non-governmental organization. NAS is part of the National Academies of Sciences, Engineering, and Medicine, along with the National Academy of Engineering (NAE) and the Nati ...
(1953) and the
Swedish Royal Academy of Sciences
The Royal Swedish Academy of Sciences ( sv, Kungliga Vetenskapsakademien) is one of the royal academies of Sweden. Founded on 2 June 1739, it is an independent, non-governmental scientific organization that takes special responsibility for prom ...
. He was awarded by Sweden with the
Order of the Polar Star
The Royal Order of the Polar Star ( Swedish: ''Kungliga Nordstjärneorden'') is a Swedish order of chivalry created by King Frederick I on 23 February 1748, together with the Order of the Sword and the Order of the Seraphim.
The Order of t ...
.
Personal life
Hille was married to Kirsti Ore Hille (1906–2001) in 1937, sister of
Norwegian
Norwegian, Norwayan, or Norsk may refer to:
*Something of, from, or related to Norway, a country in northwestern Europe
* Norwegians, both a nation and an ethnic group native to Norway
* Demographics of Norway
*The Norwegian language, including ...
mathematician
Øystein Ore. They had two sons, Harald and
Bertil Hille.
Works
*with
Ralph Phillips''Functional Analysis and Semi-Groups.''1948, 1957.
*''Analytic Function Theory.'' 2 vols., 1959, 1964.
*''Analysis.'' 2 vols., 1964, 1966.
*''Lectures on Ordinary Differential Equations.'' 1969.
*''Methods in Classical and Functional Analysis.'' 1972.
*''Ordinary Differential Equations in the Complex Domain.'' 1976.
*''In Retrospect.'' Mathematical Intelligencer, Vol.3, 1980/81, No.1, pp. 3–13.
References
Other sources
*
*
*
External links
*
{{DEFAULTSORT:Hille, Einar
1894 births
1980 deaths
20th-century American mathematicians
Mathematical analysts
American people of Swedish descent
Members of the United States National Academy of Sciences
Order of the Polar Star
Stockholm University alumni
Presidents of the American Mathematical Society
Members of the Royal Swedish Academy of Sciences