Issai Schur
Encyclopedia
Issai Schur was a mathematician
who worked in Germany
for most of his life. He studied at Berlin
. He obtained his doctorate
in 1901, became lecturer
in 1903 and, after a stay at Bonn
, professor
in 1919.
He considered himself German rather than Jewish, even though he had been born in the Russian Empire
in what is now Belarus
, and brought up partly in Latvia
. For this reason he declined invitations to leave Germany for the United States
and Britain
in 1934. Nevertheless he was dismissed from his chair in 1935 and, at the instigation of Ludwig Bieberbach
(who had previously sympathised with Schur regarding his treatment at the hands of the Nazis
), he was forced to resign from the Prussian Academy
in 1938. Schur eventually emigrated to Palestine in 1939, and lived his final years in poverty. He died in Tel Aviv on his 66th birthday
.
As a student of Frobenius
, he worked on group representation
s (the subject with which he is most closely associated), but also in combinatorics
and number theory and even theoretical physics
. He is perhaps best known today for his result on the existence of the Schur decomposition
and for his work on group representations (Schur's lemma
).
Schur had a number of students, including Richard Brauer
, B. H. Neumann, Heinz Prüfer
, and Richard Rado
.
He was a foreign member of the Russian Academy of Sciences
from 1929.
Schur published under the name of both I. Schur, and J. Schur, the latter especially in Journal für die reine und angewandte Mathematik. This has led to some confusion.
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....
who worked in Germany
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...
for most of his life. He studied at Berlin
Berlin
Berlin is the capital city of Germany and is one of the 16 states of Germany. With a population of 3.45 million people, Berlin is Germany's largest city. It is the second most populous city proper and the seventh most populous urban area in the European Union...
. He obtained his doctorate
Doctorate
A doctorate is an academic degree or professional degree that in most countries refers to a class of degrees which qualify the holder to teach in a specific field, A doctorate is an academic degree or professional degree that in most countries refers to a class of degrees which qualify the holder...
in 1901, became lecturer
Lecturer
Lecturer is an academic rank. In the United Kingdom, lecturer is a position at a university or similar institution, often held by academics in their early career stages, who lead research groups and supervise research students, as well as teach...
in 1903 and, after a stay at Bonn
Bonn
Bonn is the 19th largest city in Germany. Located in the Cologne/Bonn Region, about 25 kilometres south of Cologne on the river Rhine in the State of North Rhine-Westphalia, it was the capital of West Germany from 1949 to 1990 and the official seat of government of united Germany from 1990 to 1999....
, professor
Professor
A professor is a scholarly teacher; the precise meaning of the term varies by country. Literally, professor derives from Latin as a "person who professes" being usually an expert in arts or sciences; a teacher of high rank...
in 1919.
He considered himself German rather than Jewish, even though he had been born in the Russian Empire
Russian Empire
The Russian Empire was a state that existed from 1721 until the Russian Revolution of 1917. It was the successor to the Tsardom of Russia and the predecessor of the Soviet Union...
in what is now Belarus
Belarus
Belarus , officially the Republic of Belarus, is a landlocked country in Eastern Europe, bordered clockwise by Russia to the northeast, Ukraine to the south, Poland to the west, and Lithuania and Latvia to the northwest. Its capital is Minsk; other major cities include Brest, Grodno , Gomel ,...
, and brought up partly in Latvia
Latvia
Latvia , officially the Republic of Latvia , is a country in the Baltic region of Northern Europe. It is bordered to the north by Estonia , to the south by Lithuania , to the east by the Russian Federation , to the southeast by Belarus and shares maritime borders to the west with Sweden...
. For this reason he declined invitations to leave Germany for the United States
United States
The United States of America is a federal constitutional republic comprising fifty states and a federal district...
and Britain
United Kingdom
The United Kingdom of Great Britain and Northern IrelandIn the United Kingdom and Dependencies, other languages have been officially recognised as legitimate autochthonous languages under the European Charter for Regional or Minority Languages...
in 1934. Nevertheless he was dismissed from his chair in 1935 and, at the instigation of Ludwig Bieberbach
Ludwig Bieberbach
Ludwig Georg Elias Moses Bieberbach was a German mathematician.-Biography:Born in Goddelau, near Darmstadt, he studied at Heidelberg and under Felix Klein at Göttingen, receiving his doctorate in 1910. His dissertation was titled On the theory of automorphic functions...
(who had previously sympathised with Schur regarding his treatment at the hands of the Nazis
Nazism
Nazism, the common short form name of National Socialism was the ideology and practice of the Nazi Party and of Nazi Germany...
), he was forced to resign from the Prussian Academy
Prussian Academy
Prussian Academy may refer to:*Prussian Academy of the Arts, now the Akademie der Künste, Berlin*Prussian Academy of Sciences*Prussian Military Academy...
in 1938. Schur eventually emigrated to Palestine in 1939, and lived his final years in poverty. He died in Tel Aviv on his 66th birthday
Birthday
A birthday is a day or anniversary where a person celebrates his or her date of birth. Birthdays are celebrated in numerous cultures, often with a gift, party or rite of passage. Although the major religions celebrate the birth of their founders , Christmas – which is celebrated widely by...
.
As a student of Frobenius
Ferdinand Georg Frobenius
Ferdinand Georg Frobenius was a German mathematician, best known for his contributions to the theory of differential equations and to group theory...
, he worked on group representation
Group representation
In the mathematical field of representation theory, group representations describe abstract groups in terms of linear transformations of vector spaces; in particular, they can be used to represent group elements as matrices so that the group operation can be represented by matrix multiplication...
s (the subject with which he is most closely associated), but also in combinatorics
Combinatorics
Combinatorics is a branch of mathematics concerning the study of finite or countable discrete structures. Aspects of combinatorics include counting the structures of a given kind and size , deciding when certain criteria can be met, and constructing and analyzing objects meeting the criteria ,...
and number theory and even theoretical physics
Theoretical physics
Theoretical physics is a branch of physics which employs mathematical models and abstractions of physics to rationalize, explain and predict natural phenomena...
. He is perhaps best known today for his result on the existence of the Schur decomposition
Schur decomposition
In the mathematical discipline of linear algebra, the Schur decomposition or Schur triangulation, named after Issai Schur, is a matrix decomposition.- Statement :...
and for his work on group representations (Schur's lemma
Schur's lemma
In mathematics, Schur's lemma is an elementary but extremely useful statement in representation theory of groups and algebras. In the group case it says that if M and N are two finite-dimensional irreducible representations...
).
Schur had a number of students, including Richard Brauer
Richard Brauer
Richard Dagobert Brauer was a leading German and American mathematician. He worked mainly in abstract algebra, but made important contributions to number theory...
, B. H. Neumann, Heinz Prüfer
Heinz Prüfer
Ernst Paul Heinz Prüfer was a German mathematician, who worked on abelian groups, algebraic numbers, knot theory and Sturm-Liouville theory. His advisor was Issai Schur.- See also :* Prüfer manifold...
, and Richard Rado
Richard Rado
Richard Rado FRS was a Jewish German mathematician. He earned two Ph.D.s: in 1933 from the University of Berlin, and in 1935 from the University of Cambridge. He was interviewed in Berlin by Lord Cherwell for a scholarship given by the chemist Sir Robert Mond which provided financial support to...
.
He was a foreign member of the Russian Academy of Sciences
Russian Academy of Sciences
The Russian Academy of Sciences consists of the national academy of Russia and a network of scientific research institutes from across the Russian Federation as well as auxiliary scientific and social units like libraries, publishers and hospitals....
from 1929.
Schur published under the name of both I. Schur, and J. Schur, the latter especially in Journal für die reine und angewandte Mathematik. This has led to some confusion.