**Paul Epstein** was a German mathematician best-known for his contributions to number theory.

- Paul studied at the Philanthropin Secondary School, graduating with his Abitur in 1890.
- Epstein was taught at Strasbourg by Christoffel who became his thesis advisor.
- After submitting his thesis Zur Lehre von den hyperelliptischen Integralen Ⓣ(On the theory of hyperelliptic integrals) on abelian functions, Epstein received his doctorate in 1895 from the University of Strasbourg.
- Epstein also explains in this paper that, as well as being inspired by Christoffel's lectures, his work was based on ideas by Karl Weierstrass and others.
- At the end of the war in 1918, however, the city of Strasbourg reverted to France, and Epstein, being German, was forced to leave Alsace.
- In the first part of Zur Theorie allgemeiner Zetafunctionen Ⓣ(On the theory of general zeta functions) (1903) Epstein introduced a function belonging to a class of Dirichlet series generalising the Riemann Zeta-function depending on a given quadratic form.
- Today these function are known as the Epstein Zeta-functions.
- Forced to leave Strasbourg and having no position to go to, Epstein returned to his native city of Frankfurt.
- Epstein sought to eliminate the most obvious and the best known contradiction between Goethe and mathematics by showing that ultimately both approaches to understanding the world had their source in the same motivation and led to the same goal.
- With these texts, Epstein joined the ranks of German-Jewish intellectuals who attached great importance to the classical German educational ideal known as "Bildung".
- We know that in the summer of 1928 Epstein lectured on Étienne Pascal in the History of Mathematics seminar and hand-written lecture notes from this course survive.
- Epstein certainly qualified under this clause and this allowed him to keep his lecturing post in Frankfurt in 1933.
- Epstein did not attempt to emigrate.
- The Gestapo broke into Epstein's house but found that he was seriously ill and could not be moved.
- At this point Epstein must have known that his only chance was to leave Germany.
- Tilly Epstein was a teacher at the Philanthropin Secondary School in Frankfurt from 1901.
- She emigrated to England, but this was not until 1941 after Paul Epstein had committed suicide.
- Let us return to the story of Epstein's last days.
- Epstein's most important work was in number theory, in particular the zeta function which we mentioned above.
- Perhaps we should mention one other of Epstein's talents which was music, and he took part energetically in the cultural life of Frankfurt.

Born 24 July 1871, Frankfurt, Germany. Died 11 August 1939, Frankfurt, Germany.

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Origin Germany

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