**Hans Reichardt** was a German mathematician who worked in number theory, the history of mathematics and differential geometry.

- Hans attended the Humanistic Gymnasium in Altenburg where he learnt the three ancient languages of Latin, Greek and Hebrew.
- This did not affect Reichardt directly but it had a major affect on the lecturers in the universities in which he obtained posts.
- Reichardt's post was only for a one year and, in 1935, he moved to Jena where he was appointed as Friedrich Karl Schmidt's assistant.
- One year later, Reichardt was appointed as his assistant.
- Reichardt spent two years in this position during which time he published four further papers Die Diskriminante einer normalen einfachen Algebra Ⓣ(The discriminant of a normal simple algebra); Der Primdivisorsatz für algebraische Funktionenkörper über einem Konstantenkörper Ⓣ(The prime divisor thereom for an algebraic function field over a constant field); Über Normalkörper mit Quaternionengruppe Ⓣ(On normal fields with the quaternion group); and Eine Bemerkung zur vorstehenden Arbeit von F K Schmidt Ⓣ(A comment on earlierwork of F K Schmidt).
- In 1937 Reichardt moved again, this time going to the University of Leipzig where he worked under Bartel van der Waerden who had been appointed professor of mathematics there in 1931.
- Although working in Germany, van der Waerden refused to give up his Dutch citizenship and this was making his life very difficult around the time Reichardt became his assistant in 1937.
- Reichardt worked mainly on two particular areas of algebraic number theory, namely on the inverse problem of Galois theory and on the rational points on an elliptic curve.
- During the war Reichardt kept his position on the staff at the University of Leipzig but did war work for the navy and, from 1943, worked in Berlin for Telefunken AG, one of the major producers of electrical and communications equipment.
- After the war, from 1946 to 1952 Reichardt was in the Soviet Union, where he worked on problems of missile technology on the island of Gorodomlja in Lake Seliger in the Valdai Hills which is the source of the river Volga.
- Reichardt returned to Germany from the Soviet Union in 1952 when he was appointed extraordinary professor at the Humboldt University in Berlin.
- In 1959, in addition to his university chair, Reichardt was appointed as Director of the Institute of Pure Mathematics of the Berlin Academy of Sciences where he also headed the number theory research group.
- In the 1960s Reichardt was a founding organiser of the Mathematical Olympiad Competitions in the German Democratic Republic.
- Reichardt's mathematical interests turned towards differential geometry and later towards the history of mathematics.
- Reichardt continued his deep interest in Gauss and his contributions, publishing Gauss und die nicht-euklidische Geometrie Ⓣ(Gauss and non-Euclidean geometry) in 1976.
- Nine years later, in 1985, Reichardt published Gauss und die Anfänge der nicht-euklidischen Geometrie Ⓣ(Gauss and the beginnings of non-Euclidean geometry).
- This book contains a reprint of Reichardt's 1976 book Gauss und die nicht-euklidische Geometrie Ⓣ(Gauss and non-Euclidean geometry) but to this had been added reprints of papers on non-euclidean geometry by Janos Bolyai, Nikolai Ivanovich Lobachevsky and Felix Klein.
- We should mention another aspect of Reichardt's contributions, namely his work with the Heinrich-Hertz-Gymnasium in Berlin.
- The high school was named after the physicist Heinrich Hertz in 1961 but the school only received its mathematical emphasis in 1965 through the efforts of Reichardt and his colleague at the Humboldt University in Berlin, Heinrich Grell (1903-1974).
- After undertaking war work, he was reinstated and appointed as a professor at the Humboldt University in 1948 where he was joined by Reichardt four years later.
- He was also a colleague of Reichardt's in the German Academy of Sciences where the two worked closely.
- Reichardt and Grell were the driving force behind the movement of the Heinrich-Hertz-Gymnasium towards being a specialist mathematics school and, by 1969 when it moved to new buildings, all classes in the school were mathematically oriented.
- Reichardt, who became professor emeritus in 1973, received many honours for his contributions.

Born 2 April 1908, Altenburg, Germany. Died 4 April 1991, Berlin, Germany.

View full biography at MacTutor

Origin Germany

**O’Connor, John J; Robertson, Edmund F**: MacTutor History of Mathematics Archive