Einar Hille

Einar Carl Hille ( born June 28, 1894 in New York; † February 12, 1980 in La Jolla, originally Carl Einar Heuman ) was an American, who grew up in Sweden mathematician who worked on mathematical and functional analysis.

Life and work

Hilles parents separated before his birth and he was raised by his mother alone. His parents came from Sweden, where his mother moved with him when he was two years old. There he went to school in Stockholm and began in 1911 to study chemistry at the later Nobel laureate Hans von Euler - Chelpin. He even published some work in chemistry, but later switched to mathematics and studied at Ivar Bendixson and Helge von Koch. In 1914 he received his degree. In 1916 he wrote his Lizentiatsthese with Marcel Riesz on conformal mappings, and in 1918 he received his doctorate with a thesis on spherical harmonics. For this he received the 1919 Mittag-Leffler Prize and received the venia Legendi. In 1920 he went on a scholarship to Harvard University to George David Birkhoff and Oliver Kellogg. 1921/22, he was Benjamin Peirce Instructor at Harvard and 1922 Instructor in Princeton. In 1923 he became assistant professor in 1927 and associate professor in Princeton and in 1933 professor at Yale University. In 1938, he was Director of Graduate Studies. In 1962 he retired.

Hille worked on various topics of analysis, especially differential and integral equations, special functions, Dirichlet series and Fourier series. Later he turned to more of functional analysis, but was always interested in their applications in classical analysis, to less abstract questions. He is well known for the development of the theory of semigroups of operators on Hilbert spaces.

1937/38, he was president of the American Mathematical Society ( AMS) AMS Colloquium Lecturer in 1944. He was a member of the National Academy of Sciences (1953) and the Royal Swedish Academy of Sciences. He was awarded the Swedish Order of the North Star. In 1962 he was invited speaker at the International Congress of Mathematicians in Stockholm ( linear fourth order differential equations ).

He was since 1937 the mathematician Kirsti Hille, sister of Oystein Ore, married, with whom he has two sons, one of which the biologist Bertil Hille.

His doctoral include Irving Segal, Frederic Bohnenblust, Thomas Saaty.

Writings

• With Ralph Phillips: Functional Analysis and Semi -Groups. 1948, 1957.
• Analytic Function Theory. 2 volumes, 1959, 1964.
• Analysis. 2 volumes, 1964, 1966.
• Lectures on Ordinary Differential Equations. In 1969.
• Methods in Classical and Functional Analysis. In 1972.
• Ordinary Differential Equations in the Complex Domain. In 1976.
• In Retrospect. Mathematical Intelligencer, Vol.3, 1980/81, No.1, pp. 3-13.