Robert Erich Remak (14 February 1888 – 13 November 1942) was a German mathematician. He is chiefly remembered for his work in
group theory
In abstract algebra, group theory studies the algebraic structures known as group (mathematics), groups.
The concept of a group is central to abstract algebra: other well-known algebraic structures, such as ring (mathematics), rings, field ( ...
(
Remak decomposition). His other interests included
algebraic number theory
Algebraic number theory is a branch of number theory that uses the techniques of abstract algebra to study the integers, rational numbers, and their generalizations. Number-theoretic questions are expressed in terms of properties of algebraic ob ...
,
mathematical economics
Mathematical economics is the application of Mathematics, mathematical methods to represent theories and analyze problems in economics. Often, these Applied mathematics#Economics, applied methods are beyond simple geometry, and may include diff ...
and
geometry of numbers
Geometry of numbers is the part of number theory which uses geometry for the study of algebraic numbers. Typically, a ring of algebraic integers is viewed as a lattice (group), lattice in \mathbb R^n, and the study of these lattices provides fundam ...
. Robert Remak was the son of the neurologist
Ernst Julius Remak and the grandson of the embryologist
Robert Remak
Robert Remak (26 July 1815 – 29 August 1865) was an embryologist, physiologist and neurologist, born in Posen, Prussia, who discovered that the origin of cells was by the division of pre-existing cells. as well as several other key discoverie ...
. He was murdered in
the Holocaust
The Holocaust (), known in Hebrew language, Hebrew as the (), was the genocide of History of the Jews in Europe, European Jews during World War II. From 1941 to 1945, Nazi Germany and Collaboration with Nazi Germany and Fascist Italy ...
.
Biography
Robert Remak was born in
Berlin
Berlin ( ; ) is the Capital of Germany, capital and largest city of Germany, by both area and List of cities in Germany by population, population. With 3.7 million inhabitants, it has the List of cities in the European Union by population withi ...
. He studied at
Humboldt University of Berlin
The Humboldt University of Berlin (, abbreviated HU Berlin) is a public research university in the central borough of Mitte in Berlin, Germany.
The university was established by Frederick William III on the initiative of Wilhelm von Humbol ...
under
Ferdinand Georg Frobenius
Ferdinand Georg Frobenius (26 October 1849 – 3 August 1917) was a German mathematician, best known for his contributions to the theory of elliptic functions, differential equations, number theory, and to group theory. He is known for the famou ...
and received his doctorate in 1911. His dissertation, ''Über die Zerlegung der endlichen Gruppen in indirekte unzerlegbare Faktoren'' ("On the decomposition of a finite group into indirect indecomposable factors") established that any two decompositions of a
finite group
In abstract algebra, a finite group is a group whose underlying set is finite. Finite groups often arise when considering symmetry of mathematical or physical objects, when those objects admit just a finite number of structure-preserving tra ...
into a
direct product
In mathematics, a direct product of objects already known can often be defined by giving a new one. That induces a structure on the Cartesian product of the underlying sets from that of the contributing objects. The categorical product is an abs ...
are related by a central automorphism. A weaker form of this statement, uniqueness, was first proved by
Joseph Wedderburn
Joseph Henry Maclagan Wedderburn FRSE FRS (2 February 1882 – 9 October 1948) was a Scottish mathematician, who taught at Princeton University for most of his career. A significant algebraist, he proved that a finite division algebra is a fi ...
in 1909. Later the theorem was generalized by
Wolfgang Krull
Wolfgang Krull (26 August 1899 – 12 April 1971) was a German mathematician who made fundamental contributions to commutative algebra, introducing concepts that are now central to the subject.
Krull was born and went to school in Baden-Baden. H ...
and
Otto Schmidt
Otto Yulyevich Shmidt (born Otto Friedrich Julius Schmidt; – 7 September 1956), better known as Otto Schmidt, was a Soviet scientist, mathematician, astronomer, geophysicist, statesman, and academician.
Biography
He was born in the town of ...
to some classes of infinite groups and became known as the
Krull–Schmidt theorem or the Krull–Remak–Schmidt theorem.
Although the dissertation was first submitted in 1911, it was rejected several times and Remak did not obtain his
Habilitation
Habilitation is the highest university degree, or the procedure by which it is achieved, in Germany, France, Italy, Poland and some other European and non-English-speaking countries. The candidate fulfills a university's set criteria of excelle ...
until 1929. In the meantime, he wrote several papers on the
geometry of numbers
Geometry of numbers is the part of number theory which uses geometry for the study of algebraic numbers. Typically, a ring of algebraic integers is viewed as a lattice (group), lattice in \mathbb R^n, and the study of these lattices provides fundam ...
. Between 1929 and 1933 Remak lectured as a
Privatdozent
''Privatdozent'' (for men) or ''Privatdozentin'' (for women), abbreviated PD, P.D. or Priv.-Doz., is an academic title conferred at some European universities, especially in German-speaking countries, to someone who holds certain formal qualifi ...
at Humboldt University. In the 1929 essay ''Kann die Volkwirtschaftslehre eine exakte Wissenschaft werden?'' ("Can economics become an exact science?"), Remak analyzed price formation in socialist and capitalist economies. He also anticipated the role played by digital
computer
A computer is a machine that can be Computer programming, programmed to automatically Execution (computing), carry out sequences of arithmetic or logical operations (''computation''). Modern digital electronic computers can perform generic set ...
s in
numerical solution
Numerical analysis is the study of algorithms that use numerical approximation (as opposed to symbolic manipulations) for the problems of mathematical analysis (as distinguished from discrete mathematics). It is the study of numerical methods t ...
of
systems of linear equations
In mathematics, a system of linear equations (or linear system) is a collection of two or more linear equations involving the same variables.
For example,
: \begin
3x+2y-z=1\\
2x-2y+4z=-2\\
-x+\fracy-z=0
\end
is a system of three equations in ...
. Remak's analysis may have influenced
John von Neumann
John von Neumann ( ; ; December 28, 1903 – February 8, 1957) was a Hungarian and American mathematician, physicist, computer scientist and engineer. Von Neumann had perhaps the widest coverage of any mathematician of his time, in ...
, who was a fellow lecturer in Berlin, but most of it has not been translated into English and it remains little known and appreciated in the English-speaking world.
[Kurz and Salvadori, pp 40–46.] In 1932 Remak published a paper giving a lower bound for the
regulator of an
algebraic number field
In mathematics, an algebraic number field (or simply number field) is an extension field K of the field of rational numbers such that the field extension K / \mathbb has finite degree (and hence is an algebraic field extension).
Thus K is a ...
in terms of the numbers ''r''
1 and ''r''
2 of real embeddings and pairs of complex embeddings. He went on to investigate relations between the regulator and the
discriminant of an algebraic number field
In mathematics, the discriminant of an algebraic number field is a numerical invariant that, loosely speaking, measures the size of the (ring of integers of the) algebraic number field. More specifically, it is proportional to the squared volum ...
, isolating an important class of
CM-field
In mathematics, a CM-field is a particular type of number field, so named for a close connection to the theory of complex multiplication. Another name used is J-field.
The abbreviation "CM" was introduced by .
Formal definition
A number field '' ...
s ("fields with unit defect"). His last two papers on the subject appeared in ''
Compositio Mathematica
''Compositio Mathematica'' is a monthly peer-reviewed mathematics journal established by L.E.J. Brouwer in 1935. It is owned by the Foundation Compositio Mathematica, and since 2004 it has been published on behalf of the Foundation by the London ...
'' in 1952 and 1954, more than ten years after his death.
After the
Nazis seized power in 1933 and the
Civil Service Law was passed a few months later, Remak, who was of Jewish ancestry, lost his right to teach in September 1933. He was arrested on
Kristallnacht
( ) or the Night of Broken Glass, also called the November pogrom(s) (, ), was a pogrom against Jews carried out by the Nazi Party's (SA) and (SS) paramilitary forces along with some participation from the Hitler Youth and German civilia ...
, 9 November 1938, and was interned at
Sachsenhausen concentration camp
Sachsenhausen () or Sachsenhausen-Oranienburg was a German Nazi concentration camp in Oranienburg, Germany, used from 1936 until April 1945, shortly before the defeat of Nazi Germany in May later that year. It mainly held political prisoners t ...
for several weeks. After an unsuccessful campaign by his wife to secure a permission for him to emigrate to the United States, he was released and permitted to leave for
Amsterdam
Amsterdam ( , ; ; ) is the capital of the Netherlands, capital and Municipalities of the Netherlands, largest city of the Kingdom of the Netherlands. It has a population of 933,680 in June 2024 within the city proper, 1,457,018 in the City Re ...
. In 1942, however, he was arrested by the German occupational authorities in the Netherlands and deported to
Auschwitz
Auschwitz, or Oświęcim, was a complex of over 40 concentration and extermination camps operated by Nazi Germany in occupied Poland (in a portion annexed into Germany in 1939) during World War II and the Holocaust. It consisted of Auschw ...
, where he was murdered.
Notes
Bibliography
* Harald Hagemann: ''Robert Remak.'' In: ''Neue Deutsche Biographie.'' Band 21. Duncker & Humblot, Berlin 2003, , p. 410ff.
* Heinz D.Kurz and Neri Salvadori, ''von Neumann's 'growth model' and the classical tradition.'' In ''Understanding "classical" economics: studies in long-period theory'', Routledge studies in the history of economics, 2003.
*
Uta C. Merzbach, ''Robert Remak and the estimation of units and regulators''. Amphora, 481–522, Birkhäuser, Basel, 1992
* Reinhard Siegmund-Schultze: ''Dokumente zur Geschichte der Mathematik. Quellen und Studien zur Emigration einer Wissenschaft.'' Band 10: ''Mathematiker auf der Flucht vor Hitler.'' Vieweg, Wiesbaden 1998,
* David C. Clar
''The Lost Scientists of World War II'' World Scientific Publishing, 2024, ISBN 978-1-80061-491-8
External links
*
*
* Willy Tiabou, Christoph Bichlmeier
Verfolgte Mathematiker
{{DEFAULTSORT:Remak, Robert
20th-century German mathematicians
Mathematical economists
German people who died in Auschwitz concentration camp
1942 deaths
1888 births
Mathematicians from Berlin
German civilians killed in World War II
German Jews who died in the Holocaust
Lists of stolpersteine in Germany
Humboldt University of Berlin alumni