**Theodor Schneider** was a German mathematician, best known for his solution of Hilberts 7th problem.

- Joseph owned a fabric store in Frankfurt am Main and it was in that city that Theodor was brought up.
- This school, founded in 1912, had a strong emphasis on science so one might have thought that Schneider would want to carry on his study of the sciences after graduating from the Gymnasium in 1929.
- Frankfurt University, with this array of teaching talent, was an exciting place when Schneider entered it, and as a consequence the number of students taking mathematics courses had built up over the previous few years.
- A student as mathematically talented as Schneider was always going to be converted to mathematics by such inspiring teachers, and indeed it was not long before he had dropped other sciences to concentrate on mathematics.
- A course on transcendental numbers, given by Carl Siegel, was so inspiring that Schneider decided that he wanted to enter Siegel's research seminar and he passed the difficult entrance examination.
- Siegel gave Schneider a number of possible problems which he might work on for his doctorate.
- However, Schneider had so loved Siegel's course on transcendental numbers that he began to look at one of the open problems that Siegel had listed in that course.
- Using Gelfond's ideas, Siegel showed how to prove this for a real quadratic bbb and he gave an indication of this in his course on transcendental numbers that Schneider attended.
- Gelfond had also, independently, managed to extend the ideas in his 1929 paper to complete the proof of Hilbert's Seventh Problem so the result is now known as the Gelfond-Schneider Theorem.
- Schneider published his proof of Hilbert's Seventh Problem in the paper Transzendenzuntersuchungen periodischer Funktionen Ⓣ(Investigations of the transcendence of periodic functions) (1934) which appeared in Crelle's Journal.
- Schneider then produced another five pages on transcendence of elliptic functions and the two parts formed his thesis, also entitled Transzendenzuntersuchungen periodischer Funktionen Ⓣ(Investigations of the transcendence of periodic functions), which earned him a doctorate in 1934.
- If Schneider wanted to carry on with his studies or find a university post, he would have to join a Nazi organisation.
- Schneider was not Jewish but he was closely associated with his teachers Dehn, Epstein, Hellinger and Szász who were all Jewish.
- His closest association was with Carl Siegel who, although not Jewish, made no secret of his anti-Nazi views and this was perhaps the most damaging of all Schneider's difficulties with the Nazis.
- This might look at first as if Schneider was going too far in his efforts to be accepted, but in fact this is not so.
- Schneider's move worked and he was appointed as an assistant at Frankfurt am Main in 1935.
- The work on transcendence which had led Schneider to his solution of Hilbert's Seventh Problem led him to extend to a more general programme studying the transcendence of elliptic functions, modular functions and abelian functions.
- After his habilitation was rejected by Frankfurt, Schneider moved to Göttingen to become Siegel's assistant (a very lowly position for someone with his outstanding record).
- Of course, by 1940 Germany was at war and Schneider was drafted into the German army.
- In 1944 Schneider, still undertaking war service, received a request to go to the University of Göttingen to cover for Helene Braun who had contracted diphtheria.
- Once Schneider was in Göttingen, he was brought by Süss to Oberwolfach in March 1945.
- In May 1945 Germany surrendered but Schneider remained at the Oberwolfach Mathematical Institute until the autumn of that year by which time Göttingen University had reopened.
- Schneider's students, writing about her, made it clear how much they appreciated her.
- In 1953 Schneider was named as an ordinary professor at Erlangen.
- Süss had been the first director of the Oberwolfach Institute but, following his death, Hellmuth Kneser served as director of the institute until Schneider was appointed to that role in 1959.
- Schneider kept his close association with Oberwolfach, however, being an organiser of the number theory meetings (along with Helmut Hasse and Peter Roquette) held every year or two from 1955 to 1972.
- Let us look briefly at the important monograph Einführung in die transzendenten Zahlen Ⓣ(Introduction to transcendental numbers) (1957) by Schneider which was also published in French translation two years later as Introduction aux nombres transcendants Ⓣ(Introduction to transcendental numbers).

Born 7 May 1911, Frankfurt am Main, Germany. Died 31 October 1988, Zähringen, Freiburg, Germany.

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Origin Germany

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