Frigyes Riesz ( hu, Riesz Frigyes, , sometimes spelled as Frederic; 22 January 1880 – 28 February 1956) was a HungarianEberhard Zeidler: Nonlinear Functional Analysis and Its Applications: Linear monotone operators. Springer, 199

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mathematician A mathematician is someone who uses an extensive knowledge of mathematics in their work, typically to solve mathematical problems. Mathematicians are concerned with numbers, data, quantity, structure, space, models, and change. History On ...

who made fundamental contributions to

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 (e.g. inner product, norm, topology, etc.) and the linear functions defi ...

, as did his younger brother Marcel Riesz.

Life and career

He was born into a

Jewish Jews ( he, יְהוּדִים, , ) or Jewish people are an ethnoreligious group and nation originating from the Israelites Israelite origins and kingdom: "The first act in the long drama of Jewish history is the age of the Israelites""The ...

family in

Győr Győr ( , ; german: Raab, links=no; names in other languages) is the main city of northwest Hungary, the capital of Győr-Moson-Sopron County and Western Transdanubia region, and – halfway between Budapest and Vienna – situated on one of ...

Austria-Hungary Austria-Hungary, often referred to as the Austro-Hungarian Empire,, the Dual Monarchy, or Austria, was a constitutional monarchy and great power in Central Europe between 1867 and 1918. It was formed with the Austro-Hungarian Compromise of ...

and died in

Budapest Budapest (, ; ) is the capital and most populous city of Hungary. It is the ninth-largest city in the European Union by population within city limits and the second-largest city on the Danube river; the city has an estimated population o ...

Hungary Hungary ( hu, Magyarország ) is a landlocked country in Central Europe. Spanning of the Carpathian Basin, it is bordered by Slovakia to the north, Ukraine to the northeast, Romania to the east and southeast, Serbia to the south, Cr ...

. Between 1911 and 1919 he was a professor at the Franz Joseph University in

Kolozsvár ; hu, kincses város) , official_name=Cluj-Napoca , native_name= , image_skyline= , subdivision_type1 = County , subdivision_name1 = Cluj County , subdivision_type2 = Status , subdivision_name2 = County seat , settlement_type = City , l ...

, Austria-Hungary. The post-WW1

Treaty of Trianon The Treaty of Trianon (french: Traité de Trianon, hu, Trianoni békeszerződés, it, Trattato del Trianon) was prepared at the Paris Peace Conference and was signed in the Grand Trianon château in Versailles on 4 June 1920. It forma ...

transferred former Austro-Hungarian territory including Kolozsvár to the

Kingdom of Romania The Kingdom of Romania ( ro, Regatul României) was a constitutional monarchy that existed in Romania from 13 March ( O.S.) / 25 March 1881 with the crowning of prince Karl of Hohenzollern-Sigmaringen as King Carol I (thus beginning the Romanian ...

, whereupon Kolozsvár's name changed to

Cluj ; hu, kincses város) , official_name=Cluj-Napoca , native_name= , image_skyline= , subdivision_type1 = County , subdivision_name1 = Cluj County , subdivision_type2 = Status , subdivision_name2 = County seat , settlement_type = City , ...

and the University of Kolozsvár moved to

Szeged Szeged ( , ; see also other alternative names) is the third largest city of Hungary, the largest city and regional centre of the Southern Great Plain and the county seat of Csongrád-Csanád county. The University of Szeged is one of the m ...

, Hungary, becoming the

University of Szeged , mottoeng = Truth. Bravery. Freedom. , established = , type = Public research university , founder = Emperor Franz Joseph I , affiliation = European University Association, Science Without Borders, Confucius Institute , budget = US$220 m ...

. Then, Riesz was the

rector Rector (Latin for the member of a vessel's crew who steers) may refer to: Style or title *Rector (ecclesiastical), a cleric who functions as an administrative leader in some Christian denominations *Rector (academia), a senior official in an edu ...

and a professor at the University of Szeged, as well as a member of the

Hungarian Academy of Sciences The Hungarian Academy of Sciences ( hu, Magyar Tudományos Akadémia, MTA) is the most important and prestigious learned society of Hungary. Its seat is at the bank of the Danube in Budapest, between Széchenyi rakpart and Akadémia utca. Its ma ...

. and the

Polish Academy of Learning The Polish Academy of Arts and Sciences or Polish Academy of Learning ( pl, Polska Akademia Umiejętności), headquartered in Kraków and founded in 1872, is one of two institutions in contemporary Poland having the nature of an academy of scie ...

. He was the older brother of the mathematician Marcel Riesz. Riesz did some of the fundamental work in developing

and his work has had a number of important applications in physics. He established the

spectral theory In mathematics, spectral theory is an inclusive term for theories extending the eigenvector and eigenvalue theory of a single square matrix to a much broader theory of the structure of operators in a variety of mathematical spaces. It is a result ...

for bounded symmetric operators in a form very much like that now regarded as standard. He also made many contributions to other areas including

ergodic theory Ergodic theory ( Greek: ' "work", ' "way") is a branch of mathematics that studies statistical properties of deterministic dynamical systems; it is the study of ergodicity. In this context, statistical properties means properties which are expr ...

topology In mathematics, topology (from the Greek words , and ) is concerned with the properties of a geometric object that are preserved under continuous deformations, such as stretching, twisting, crumpling, and bending; that is, without closing ...

and he gave an elementary proof of the mean ergodic theorem. Riesz founded the

Acta Scientiarum Mathematicarum ''Acta Scientiarum Mathematicarum'' is a Hungarian mathematical journal published by the János Bolyai Mathematical Institute (University of Szeged). It was established by Alfréd Haar and Frigyes Riesz in 1922. The current editor-in-chief is Lajo ...

journal together with

Alfréd Haar Alfréd Haar ( hu, Haar Alfréd; 11 October 1885, Budapest – 16 March 1933, Szeged) was a Kingdom of Hungary, Hungarian mathematician. In 1904 he began to study at the University of Göttingen. His doctorate was supervised by David Hil ...

. He had an uncommon method of giving lectures: he entered the lecture hall with an assistant and a

docent The title of docent is conferred by some European universities to denote a specific academic appointment within a set structure of academic ranks at or below the full professor rank, similar to a British readership, a French " ''maître de conf ...

. The docent then began reading the proper passages from Riesz's handbook and the assistant wrote the appropriate equations on the blackboard—while Riesz himself stood aside, nodding occasionally. The Swiss-American mathematician

Edgar Lorch Edgar Raymond Lorch (July 22, 1907 – March 5, 1990) was a Swiss American mathematician. Described by '' The New York Times'' as "a leader in the development of modern mathematics theory", he was a professor of mathematics at Columbia Universi ...

spent 1934 in Szeged working under Riesz and wrote a reminiscence about his time there, including his collaboration with Riesz. The corpus of his bibliography was compiled by the mathematician Pál Medgyessy.Pál Medgyessy's entry
in ''Tudósnaptár'' ("Calendar of Scientists")

Publications

References

External links

* * * {{DEFAULTSORT:Riesz, Frigyes 1880 births 1956 deaths University of Szeged faculty 19th-century Hungarian mathematicians 20th-century Hungarian mathematicians Mathematical analysts Functional analysts Operator theorists Mathematicians from Budapest Members of the Hungarian Academy of Sciences Burials at Kerepesi Cemetery Franz Joseph University faculty Rectors of the Franz Joseph University Austro-Hungarian mathematicians

Life and career

Publications

See also

References

External links