Ernst Jacobsthal German mathematician
German mathematician
Intro  German mathematician  
A.K.A.  Ernst Erich Jacobsthal  
Countries  Germany Norway  
Occupations  Mathematician Professor Educator  
Gender  male  
Birth  16 October 1882 (Berlin)  
Death  6 February 1965 (Überlingen)  
Star sign  Libra  
Family 

Ernst Erich Jacobsthal (16 October 1882, Berlin – 6 February 1965, Überlingen) was a German mathematician, and brother to the archaeologist Paul Jacobsthal.
In 1906, he earned his PhD at the University of Berlin, where he was a student of Georg Frobenius, Hermann Schwarz and Issai Schur; his dissertation, Anwendung einer Formel aus der Theorie der quadratischen Reste (Application of a Formula from the Theory of Quadratic Remainders), provided a proof that prime numbers of the form 4n + 1 are the sum of two square numbers. In 1934, he was fired from his professorship at the Technische Hochschule Berlin, because of his Jewish origins. In 1939 he fled to Norway and became after the war a professor at the technical university of Trondheim.