Background
Einar Hille was born in New York to Swedish immigrant parents. He was the son of Carl August Heuman, a civil engineer, and Edla Eckman. When Einar Hille was two years old his mother returned to Sweden and lived in Stockholm.
Einar Hille was born in New York to Swedish immigrant parents. He was the son of Carl August Heuman, a civil engineer, and Edla Eckman. When Einar Hille was two years old his mother returned to Sweden and lived in Stockholm.
Einar 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.
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.
Hille's main work was on integral equations, differential equations, special functions, Dirichlet series and Fourier series. 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. Hille served as president of the American Mathematical Society (1937–38) and was the Society's Colloquium lecturer in 1944.
Hille was married to Kirsti Ore Hille (1906–2001), sister of Norwegian mathematician Øystein Ore. They had two sons, Harald and Bertil Hille.