Isaac Jacob Schoenberg (April 21, 1903, Galaţi

Galati

Galați is a city and municipality in Romania, the capital of Galați County. Located in the historical region of Moldavia, in the close vicinity of Brăila, Galați is the largest port and sea port on the Danube River and the second largest Romanian port....

—February 21, 1990) was a Romanian

Romanians

The Romanians are an ethnic group native to Romania, who speak Romanian; they are the majority inhabitants of Romania....

 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....

, known for his discovery of splines

Spline (mathematics)

In mathematics, a spline is a sufficiently smooth piecewise-polynomial function. In interpolating problems, spline interpolation is often preferred to polynomial interpolation because it yields similar results, even when using low-degree polynomials, while avoiding Runge's phenomenon for higher...

.

He studied at the University of Iaşi, receiving his M.A. in 1922. From 1922 to 1925 he studied at the Universities of Berlin

Humboldt University of Berlin

The Humboldt University of Berlin is Berlin's oldest university, founded in 1810 as the University of Berlin by the liberal Prussian educational reformer and linguist Wilhelm von Humboldt, whose university model has strongly influenced other European and Western universities...

 and Göttingen, working on a topic in analytic number theory suggested by Issai Schur

Issai Schur

Issai Schur was a mathematician who worked in Germany for most of his life. He studied at Berlin...

. He presented his thesis to the University of Iaşi, obtaining his Ph.D. in 1926. In Göttingen, he met Edmund Landau

Edmund Landau

Edmund Georg Hermann Landau was a German Jewish mathematician who worked in the fields of number theory and complex analysis.-Biography:...

, who arranged a visit for Schoenberg to the Hebrew University of Jerusalem

Hebrew University of Jerusalem

The Hebrew University of Jerusalem ; ; abbreviated HUJI) is Israel's second-oldest university, after the Technion – Israel Institute of Technology. The Hebrew University has three campuses in Jerusalem and one in Rehovot. The world's largest Jewish studies library is located on its Edmond J...

  in 1928. During this visit, Schoenberg began his influential work on total positivity

Totally positive matrix

In mathematics, a totally positive matrix is a matrix in which the determinant of every square submatrix is positive. For example, a Vandermonde matrix whose nodes are positive and increasing is a totally positive matrix....

 and variation-diminishing linear transformations. In 1930, he returned from Jerusalem, and married Landau's daughter Charlotte in Berlin.

In 1930, he was awarded a Rockefeller Fellowship, which enabled him to go to the United States

United States

The United States of America is a federal constitutional republic comprising fifty states and a federal district...

, visiting 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...

,
Harvard

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...

, and the Institute for Advanced Study

Institute for Advanced Study

The Institute for Advanced Study, located in Princeton, New Jersey, United States, is an independent postgraduate center for theoretical research and intellectual inquiry. It was founded in 1930 by Abraham Flexner...

 in Princeton, New Jersey

Princeton, New Jersey

Princeton is a community located in Mercer County, New Jersey, United States. It is best known as the location of Princeton University, which has been sited in the community since 1756...

. From 1935, he taught at Swarthmore College

Swarthmore College

Swarthmore College is a private, independent, liberal arts college in the United States with an enrollment of about 1,500 students. The college is located in the borough of Swarthmore, Pennsylvania, 11 miles southwest of Philadelphia....

 and Colby College

Colby College

Colby College is a private liberal arts college located on Mayflower Hill in Waterville, Maine. Founded in 1813, it is the 12th-oldest independent liberal arts college in the United States...

. In 1941, he was appointed to the faculty at the University of Pennsylvania

University of Pennsylvania

The University of Pennsylvania is a private, Ivy League university located in Philadelphia, Pennsylvania, United States. Penn is the fourth-oldest institution of higher education in the United States,Penn is the fourth-oldest using the founding dates claimed by each institution...

. During 1943–1945 he was released from U. Penn. in order to perform war work as a mathematician at the Aberdeen Proving Ground

Aberdeen Proving Ground

Aberdeen Proving Ground is a United States Army facility located near Aberdeen, Maryland, . Part of the facility is a census-designated place , which had a population of 3,116 at the 2000 census.- History :...

. It was during this time that he initiated the work for which he is most famous, the theory of splines.

In 1966 he moved to the University of Wisconsin–Madison

University of Wisconsin–Madison

The University of Wisconsin–Madison is a public research university located in Madison, Wisconsin, United States. Founded in 1848, UW–Madison is the flagship campus of the University of Wisconsin System. It became a land-grant institution in 1866...

where he became a member of the Mathematics Research Center. He remained there until he retired in 1973.

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