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. 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 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,
Princeton University,
Stanford University and the
University of Chicago. In 1933, he became an endowed professor on mathematics in the Graduate School of
Yale University, retiring in 1962.
Hille's main work was on
integral equations,
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 functions,
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 ana ...
and
Fourier series
A Fourier series () is a summation of harmonically related sinusoidal functions, also known as components or harmonics. The result of the summation is a periodic function whose functional form is determined by the choices of cycle length (or ''p ...
. Later in his career his interests turned more towards
functional analysis. 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 (1953) and the
Swedish Royal Academy of Sciences. He was awarded by Sweden with the
Order of the Polar Star.
Personal life
Hille was married to Kirsti Ore Hille (1906–2001) in 1937, sister of
Norwegian mathematician
Øystein Ore. They had two sons, Harald and
Bertil Hille
Bertil Hille (born October 10, 1940) is an Emeritus Professor, and the Wayne E. Crill Endowed Professor in the Department of Physiology and Biophysics at the University of Washington. He is particularly well known for his pioneering research on ce ...
.
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
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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