Ernst Jacobsthal
Ernst Erich Jacobsthal ( born October 16, 1882 in Berlin, † February 6, 1965 in Lingen ) was a German mathematician.
Life
Ernst Jacobsthal was the son of a physician and brother of the archaeologist Paul Jacobsthal. He studied at the Humboldt University of Berlin, Georg Frobenius, Hermann Schwarz and Schur Isay. His doctoral dissertation at the University of Berlin from 1906 in Frobenius and Schur was entitled applying a formula from the theory of quadratic residues and provided evidence that primes of the form 4n 1 can be represented as the sum of two square numbers. In 1909, he was but a teacher at the Kaiser Wilhelm Real Gymnasium in Berlin, was also an assistant to Emil lamp at the TU Berlin, where in 1913 he qualified as a professor and lecturer and associate professor in 1922 was. In 1934 he was dismissed as a Jew from his professorship. He settled then put as a high school teacher retired and emigrated to Trondheim in Norway, where at that time also Max Dehn taught alongside Viggo Brun. After the German occupation of Norway in 1940 he remained until 1943, but then left Norway in the direction of Sweden. After the war he returned to Norway, became a professor at the Norwegian Institute of Technology and a Norwegian citizen. He was also regularly until 1957 Visiting Professor at the Free University Berlin. For health reasons he moved in 1958 from Norway to Lake Constance.
In addition to number theory, he also dealt with Algebra, Combinatorics and Analysis (function theory, real analysis and number theory, differential equations).
In 1950 he became a member of the Norwegian Academy of Sciences. On October 16, 1952 his 70th birthday, he received the first honorary citizen of the FU Berlin.
He was at his own request on the Burgtorfriedhof in Lübeck in the family grave of his wife Anne Marie Jacobsthal, born Coste, buried.
The Jacobsthal sequence is named after him.
- ( Sequence A001045 in OEIS )
Writings
- Number theoretic properties of integer polynomials. Compositio Mathematica 6, 1939 PDF