Ernst Hellinger
Encyclopedia
Ernst David Hellinger was a German
mathematician
.
, Poland
) to Emil and Julie Hellinger. He grew up in Breslau, attended school and graduated from the Gymnasium there in 1902. When he was studying at the Gymnasium, he became fascinated in mathematics, due to excellent mathematics
teachers at the school.
, one of the most influential mathematicians of the 20th century.
Hellinger taught at University of Göttingen (1907–1909), University of Marburg (1909–1914), and University of Frankfurt (1914–1935).
Adolf Hitler
came to power in Germany in 1933, and while they were in power the Nazis removed several Jewish scientists and mathematicians from German universities. Hellinger's family was Jewish, and he was removed from the faculty of the University of Frankfurt in 1936.
at Evanston, Illinois
in the United States
. He was released from the Dachau camp after six weeks on condition that he emigrate immediately.
He joined the faculty at Northwestern University as lecturer in Mathematics in 1939. He became a U.S. citizen in 1944. Promoted to professor in 1945, he became emeritus in 1949. He died on March 28, 1950 in Chicago, Illinois, United States.
s, infinite system of equations, real functions and continued fraction
s. A type of integral he introduced in his dissertation became known as "the Hellinger integral
", used for defining the Hellinger distance
, and the Hilbert-Hellinger theory of forms in infinitely many variables profoundly influenced mathematical analysis
.
Germany
Germany , officially the Federal Republic of Germany , is a federal parliamentary republic in Europe. The country consists of 16 states while the capital and largest city is Berlin. Germany covers an area of 357,021 km2 and has a largely temperate seasonal climate...
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....
.
Early years
Ernst Hellinger was born on September 30, 1883 in Striegau, Silesia, Germany (now StrzegomStrzegom
Strzegom is a town in Świdnica County, Lower Silesian Voivodeship, in south-western Poland. It is the seat of the administrative district called Gmina Strzegom. It lies approximately north-west of Świdnica, and west of the regional capital Wrocław...
, Poland
Poland
Poland , officially the Republic of Poland , is a country in Central Europe bordered by Germany to the west; the Czech Republic and Slovakia to the south; Ukraine, Belarus and Lithuania to the east; and the Baltic Sea and Kaliningrad Oblast, a Russian exclave, to the north...
) to Emil and Julie Hellinger. He grew up in Breslau, attended school and graduated from the Gymnasium there in 1902. When he was studying at the Gymnasium, he became fascinated in mathematics, due to excellent mathematics
Mathematics
Mathematics is the study of quantity, space, structure, and change. Mathematicians seek out patterns and formulate new conjectures. Mathematicians resolve the truth or falsity of conjectures by mathematical proofs, which are arguments sufficient to convince other mathematicians of their validity...
teachers at the school.
Academic career
After graduating from the Gymnasium, Ernst Hellinger entered the University of Heidelberg, but didn't complete his studies there. After Heidelberg, he studied at the University of Breslau, before completing his doctorate at the University of Göttingen in 1907 with a thesis entitled Die Orthogonalinvarianten quadratischer Formen von unendlich vielen Variablen. At Göttingen, he worked with David HilbertDavid Hilbert
David Hilbert was a German mathematician. He is recognized as one of the most influential and universal mathematicians of the 19th and early 20th centuries. Hilbert discovered and developed a broad range of fundamental ideas in many areas, including invariant theory and the axiomatization of...
, one of the most influential mathematicians of the 20th century.
Hellinger taught at University of Göttingen (1907–1909), University of Marburg (1909–1914), and University of Frankfurt (1914–1935).
Adolf Hitler
Adolf Hitler
Adolf Hitler was an Austrian-born German politician and the leader of the National Socialist German Workers Party , commonly referred to as the Nazi Party). He was Chancellor of Germany from 1933 to 1945, and head of state from 1934 to 1945...
came to power in Germany in 1933, and while they were in power the Nazis removed several Jewish scientists and mathematicians from German universities. Hellinger's family was Jewish, and he was removed from the faculty of the University of Frankfurt in 1936.
Later years
On November 13, 1938, Hellinger was arrested, first taken to the Festhalle and then put into Dachau concentration camp. Fortunately friends were able to arrange a temporary job for Hellinger at Northwestern UniversityNorthwestern University
Northwestern University is a private research university in Evanston and Chicago, Illinois, USA. Northwestern has eleven undergraduate, graduate, and professional schools offering 124 undergraduate degrees and 145 graduate and professional degrees....
at Evanston, Illinois
Evanston, Illinois
Evanston is a suburban municipality in Cook County, Illinois 12 miles north of downtown Chicago, bordering Chicago to the south, Skokie to the west, and Wilmette to the north, with an estimated population of 74,360 as of 2003. It is one of the North Shore communities that adjoin Lake Michigan...
in the United States
United States
The United States of America is a federal constitutional republic comprising fifty states and a federal district...
. He was released from the Dachau camp after six weeks on condition that he emigrate immediately.
He joined the faculty at Northwestern University as lecturer in Mathematics in 1939. He became a U.S. citizen in 1944. Promoted to professor in 1945, he became emeritus in 1949. He died on March 28, 1950 in Chicago, Illinois, United States.
Contributions to mathematics
Ernst Hellinger studied integral equationIntegral 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, infinite system of equations, real functions and continued fraction
Continued fraction
In mathematics, a continued fraction is an expression obtained through an iterative process of representing a number as the sum of its integer part and the reciprocal of another number, then writing this other number as the sum of its integer part and another reciprocal, and so on...
s. A type of integral he introduced in his dissertation became known as "the Hellinger integral
Hellinger integral
In mathematics, the Hellinger integral is an integral introduced by that is a special case of the Kolmogorov integral. It is used to define the Hellinger distance in probability theory.-References:...
", used for defining the Hellinger distance
Hellinger distance
In probability and statistics, the Hellinger distance is used to quantify the similarity between two probability distributions. It is a type of f-divergence...
, and the Hilbert-Hellinger theory of forms in infinitely many variables profoundly influenced mathematical analysis
Mathematical analysis
Mathematical analysis, which mathematicians refer to simply as analysis, has its beginnings in the rigorous formulation of infinitesimal calculus. It is a branch of pure mathematics that includes the theories of differentiation, integration and measure, limits, infinite series, and analytic functions...
.