Alwin Reinhold Korselt (17 March 1864, in Mittelherwigsdorf – 4 February 1947, in

Plauen Plauen (; Czech: ''Plavno'') is, with around 65,000 inhabitants, the fifth-largest city of Saxony, Germany after Leipzig, Dresden, Chemnitz and Zwickau, the second-largest city of the Vogtland after Gera, as well as the largest city in the S ...

) was a German mathematician. He discovered Korselt's criterion, which provides a secondary definition for

Carmichael numbers In number theory, a Carmichael number is a composite number n, which in modular arithmetic satisfies the congruence relation: :b^n\equiv b\pmod for all integers b. The relation may also be expressed in the form: :b^\equiv 1\pmod. for all integers ...

and also contributed an early result in algebraic logic.

Personal life

The Korselts are a huge, widespread family that has been resident in the village of Mittelherwigsdorf near

Zittau Zittau ( hsb, Žitawa, dsb, Žytawa, pl, Żytawa, cs, Žitava, Upper Lusatian Dialect: ''Sitte''; from Slavic "'' rye''" (Upper Sorbian and Czech: ''žito'', Lower Sorbian: ''žyto'', Polish: ''żyto'')) is the southeasternmost city in the Ge ...

in Saxony (nowadays close to the Czech and Polish borders) since the early Middle Ages. Alwin Korselt was born there in 1864. After attending '' Gymnasium'' in Zittau between 1876 and 1885, he studied mathematics and physics in

Leipzig Leipzig ( , ; Upper Saxon: ) is the most populous city in the German state of Saxony. Leipzig's population of 605,407 inhabitants (1.1 million in the larger urban zone) as of 2021 places the city as Germany's eighth most populous, as ...

(with one semester in 1886 in Freiburg im Breisgau) until 1890. After a probationary year as a teacher at Nikolaigymnasium in

he taught from 1891 to 1898 at various schools in

Pirna Pirna (; hsb, Pěrno; ) is a town in Saxony, Germany and capital of the administrative district Sächsische Schweiz-Osterzgebirge. The town's population is over 37,000. Pirna is located near Dresden and is an important district town as well as ...

Dresden Dresden (, ; Upper Saxon: ''Dräsdn''; wen, label= Upper Sorbian, Drježdźany) is the capital city of the German state of Saxony and its second most populous city, after Leipzig. It is the 12th most populous city of Germany, the fourth ...

, Keilhau near

Rudolstadt Rudolstadt is a town in the German federal state Thuringia, with the Thuringian Forest to the southwest, and to Jena and Weimar to the north. The former capital of Schwarzburg-Rudolstadt, the town is built along the River Saale inside a wide v ...

Löbau Löbau ( Upper Sorbian: Lubij) is a city in the east of Saxony, Germany, in the traditional region of Upper Lusatia. It is situated between the slopes of the Löbauer Berg and the fertile hilly area of the Upper Lusatian Mountains. It is the ga ...

and

Meerane Meerane () is a town in the Zwickau district of Saxony, Germany. It lies midway between the towns of Altenburg and Zwickau, west of Chemnitz. As of 31 December 2015, there were 14,851 inhabitants. The population has declined from a peak of over 2 ...

. Frequent changes, often between very different school types, indicate that he found it difficult to gain ground in his profession. His first scientific publication, a voluminous review of Ernst Schröder's lectures on the ''Algebra of Logic'', fell into this time (finished 1893). From 1898 till his retirement in 1924 he taught at Realschule

. He never married, and was well known for his shabby appearance, which was mostly because he found it hard to spend money on anything but books and cigars. In the 1930s he lost a leg through amputation, but remained scientifically active until around 1939. He died in Plauen in 1947 and was interred in Mittelherwigsdorf.

Research

Korselt's 1902 dissertation at

Leipzig University Leipzig University (german: Universität Leipzig), in Leipzig in Saxony, Germany, is one of the world's oldest universities and the second-oldest university (by consecutive years of existence) in Germany. The university was founded on 2 December ...

(adviser

Otto Hölder Ludwig Otto Hölder (December 22, 1859 – August 29, 1937) was a German mathematician born in Stuttgart. Early life and education Hölder was the youngest of three sons of professor Otto Hölder (1811–1890), and a grandson of professor Chris ...

) was titled ''Über die Möglichkeit der Lösung merkwürdiger Dreiecksaufgaben durch Winkelteilung'' ("On the Possibility of Solving Strange Triangle Problems by Angle Dissection"). Shortly afterwards he took part in controversy with

Gottlob Frege Friedrich Ludwig Gottlob Frege (; ; 8 November 1848 – 26 July 1925) was a German philosopher, logician, and mathematician. He was a mathematics professor at the University of Jena, and is understood by many to be the father of analytic ph ...

, concerning

Hilbert's axioms Hilbert's axioms are a set of 20 assumptions proposed by David Hilbert in 1899 in his book ''Grundlagen der Geometrie'' (tr. ''The Foundations of Geometry'') as the foundation for a modern treatment of Euclidean geometry. Other well-known modern ax ...

for the foundations of

Euclidean geometry Euclidean geometry is a mathematical system attributed to ancient Greek mathematician Euclid, which he described in his textbook on geometry: the '' Elements''. Euclid's approach consists in assuming a small set of intuitively appealing axioms ...

. He was treated by Frege as a partisan of Hilbert. Korselt was influenced by

Bolzano Bolzano ( or ; german: Bozen, (formerly ); bar, Bozn; lld, Balsan or ) is the capital city of the province of South Tyrol in northern Italy. With a population of 108,245, Bolzano is also by far the largest city in South Tyrol and the third la ...

and had contact with

Pringsheim Pringsheim is a Jewish Silesian surname. Notable people with the surname include: * Alfred Pringsheim (1850–1941), mathematician, father-in-law of writer Thomas Mann * Ernst Pringsheim Sr. (1859–1917), German physicist * Ernst Pringsheim Jr. ...

Hilbert David Hilbert (; ; 23 January 1862 – 14 February 1943) was a German mathematician, one of the most influential mathematicians of the 19th and early 20th centuries. Hilbert discovered and developed a broad range of fundamental ideas in many ...

, Russell, Fraenkel and Carathéodory.

References

{{DEFAULTSORT:Korselt, Alwin Reinhold 1864 births 1947 deaths People from Görlitz (district) People from the Kingdom of Saxony 19th-century German mathematicians 20th-century German mathematicians Leipzig University alumni