Ernst Jacobsthal

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Ernst Erich Jacobsthal (born October 16, 1882 in Berlin ; † February 6, 1965 in Überlingen ) was a German mathematician.

Life

Ernst Jacobsthal was the son of a doctor and brother of the archaeologist Paul Jacobsthal . He studied at the Humboldt University in Berlin with Georg Frobenius , Hermann Schwarz and Issai Schur . His dissertation at the University of Berlin in 1906 with Frobenius and Schur was entitled Application of a Formula from the Theory of Square Residues and provided the proof that prime numbers of the form 4n + 1 can be represented as the sum of two square numbers. In 1909 he became a teacher at the Kaiser Wilhelm Realgymnasium in Berlin, but was also Emil Lampe's assistant at the TU Berlin , where he completed his habilitation in 1913 and became a private lecturer and in 1922 an associate professor. In 1934 he was dismissed from his professorship as a Jew. He then retired as a high school teacher and emigrated to Trondheim in Norway, where Max Dehn was teaching alongside Viggo Brun . After the German occupation of Norway in 1940, he stayed until 1943, but then left Norway for Sweden. After the war he returned to Norway, became a professor at the Norwegian Technical University and a Norwegian citizen. He was also a regular visiting professor at the Free University of Berlin until 1957 . For health reasons, he moved from Norway to Lake Constance in 1958.

In addition to number theory, he also dealt with algebra, combinatorics and analysis (function theory, real analysis and series theory, differential equations).

In 1950 he became a member of the Norwegian Academy of Sciences . On October 16, 1952, his 70th birthday, he was the first to receive honorary citizenship of the Free University of Berlin .

At his own request he was buried in the Burgtorfriedhof in Lübeck in the family grave of his wife Annemarie Jacobsthal, née Coste.

The Jacobsthal series is named after him.

Ernst Jacobsthal married Anne-Marie Coste (* 1883) in 1948, the daughter of the Berlin high school director David Coste (1853-1915).

Fonts

  • Number-theoretic properties of integer polynomials . Compositio Mathematica, 6, 1939 PDF

literature

Web links

personal data
SURNAME Jacobsthal, Ernst
ALTERNATIVE NAMES Jacobsthal, Ernst Erich (full name)
BRIEF DESCRIPTION German mathematician
DATE OF BIRTH October 16, 1882
PLACE OF BIRTH Berlin
DATE OF DEATH February 6, 1965
Place of death Überlingen