Carl Einar Hille was a Swedish American

Swedish American

Swedish Americans are Americans of Swedish descent, especially the descendants of about 1.2 million immigrants from Sweden during 1885-1915. Most were Lutherans who affiliated with the Evangelical Lutheran Church in America ; some were Methodists...

 mathematician

Mathematician

A mathematician is a person whose primary area of study is the field of mathematics. Mathematicians are concerned with quantity, structure, space, and change....

.

Hille was born in New York

New York City

New York is the most populous city in the United States and the center of the New York Metropolitan Area, one of the most populous metropolitan areas in the world. New York exerts a significant impact upon global commerce, finance, media, art, fashion, research, technology, education, and...

 to Swedish immigrant

Swedish emigration to the United States

During the Swedish emigration to the United States in the 19th and early 20th centuries, about 1.3 million Swedes left Sweden for the United States...

 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. Hille spent the next 24 years of his life in Sweden, returning to the United States when he was 26 years old.

Career

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

Mittag-Leffler Institute

The Mittag-Leffler Institute is a mathematical research institute located in Djursholm, a suburb of Stockholm. It invites scholars to participate in year-long or half-year programs in specialized mathematical subjects...

 Prize and was given the right to teach at the University of Stockholm. He subsequently taught at Harvard University

Harvard University

Harvard University is a private Ivy League university located in Cambridge, Massachusetts, United States, established in 1636 by the Massachusetts legislature. Harvard is the oldest institution of higher learning in the United States and the first corporation chartered in the country...

, Princeton University

Princeton University

Princeton University is a private research university located in Princeton, New Jersey, United States. The school is one of the eight universities of the Ivy League, and is one of the nine Colonial Colleges founded before the American Revolution....

, Stanford University

Stanford University

The Leland Stanford Junior University, commonly referred to as Stanford University or Stanford, is a private research university on an campus located near Palo Alto, California. It is situated in the northwestern Santa Clara Valley on the San Francisco Peninsula, approximately northwest of San...

 and the University of Chicago

University of Chicago

The University of Chicago is a private research university in Chicago, Illinois, USA. It was founded by the American Baptist Education Society with a donation from oil magnate and philanthropist John D. Rockefeller and incorporated in 1890...

. In 1933, he became an endowed professor on mathematics in the Graduate School of Yale University

Yale University

Yale University is a private, Ivy League university located in New Haven, Connecticut, United States. Founded in 1701 in the Colony of Connecticut, the university is the third-oldest institution of higher education in the United States...

. Hille was a member of the London Mathematical Society

London Mathematical Society

-See also:* American Mathematical Society* Edinburgh Mathematical Society* European Mathematical Society* List of Mathematical Societies* Council for the Mathematical Sciences* BCS-FACS Specialist Group-External links:* * *...

 and the Circolo Matematico di Palermo

Circolo Matematico di Palermo

The Circolo Matematico di Palermo is an Italian mathematical society, founded in Palermo by Sicilian geometer Giovanni B. Guccia in 1884. It began accepting foreign members in 1888, and by the time of Guccia's death in 1914 it had become the foremost international mathematical society, with...

. Hille served as president of the American Mathematical Society

American Mathematical Society

The American Mathematical Society is an association of professional mathematicians dedicated to the interests of mathematical research and scholarship, which it does with various publications and conferences as well as annual monetary awards and prizes to mathematicians.The society is one of the...

 (1937–38) and was the Society's Colloquium lecturer in 1944. He received many honours including election to the United States National Academy of Sciences

United States National Academy of Sciences

The National Academy of Sciences is a corporation in the United States whose members serve pro bono as "advisers to the nation on science, engineering, and medicine." As a national academy, new members of the organization are elected annually by current members, based on their distinguished and...

 (1953) and the Royal Academy of Sciences of Stockholm. He was awarded by Sweden with the Order of the Polar Star

Order of the Polar Star

The Order of the Polar Star is a Swedish order of chivalry created by King Frederick I of Sweden on 23 February 1748, together with the Order of the Sword and the Order of the Seraphim....

.

Hille's main work was on integral equation

Integral equation

In mathematics, an integral equation is an equation in which an unknown function appears under an integral sign. There is a close connection between differential and integral equations, and some problems may be formulated either way...

s, differential equation

Differential equation

A differential equation is a mathematical equation for an unknown function of one or several variables that relates the values of the function itself and its derivatives of various orders...

s, special functions, Dirichlet series and Fourier series

Fourier series

In mathematics, a Fourier series decomposes periodic functions or periodic signals into the sum of a set of simple oscillating functions, namely sines and cosines...

. Later in his career his interests turned more towards functional analysis

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 and the linear operators acting upon these spaces and respecting these structures in a suitable sense...

. His name persists among others in the Hille–Yosida theorem.

Hille was married to Kirsti Hille (née Ore), sister of Norwegian

Norwegians

Norwegians constitute both a nation and an ethnic group native to Norway. They share a common culture and speak the Norwegian language. Norwegian people and their descendants are found in migrant communities worldwide, notably in United States, Canada and Brazil.-History:Towards the end of the 3rd...

 mathematician Øystein Ore

Øystein Ore

Øystein Ore was a Norwegian mathematician.-Life:Ore was graduated from the University of Oslo in 1922, with a Cand.Scient. degree in mathematics. In 1924, the University of Oslo awarded him the Ph.D. for a thesis titled Zur Theorie der algebraischen Körper, supervised by Thoralf Skolem...

, and had two sons, Harald and Bertil Hille

Bertil Hille

Bertil Hille is a professor in the Department of Physiology and Biophysics at the University of Washington. He is particularly well known for his research and expertise on cell signalling by ion channels.-Early life and education:...

. He died in La Jolla, California.

External links