Theodor Estermann

Theodor Estermann (1902 to 1991) was a German-born mathematician who worked in analytic number theory. Born in Neubrandenburg to a Jewish family with Zionist convictions, he grew up between Hamburg, Berlin and, during the First World War, Jerusalem. He began at Göttingen, hearing Hilbert and Landau, then moved to the University of Hamburg, where he took his doctorate in 1925 under Hans Rademacher with a thesis on the Caratheodory and Minkowski generalisations of the notion of length. He went on to University College London, earned a D.Sc. there and joined its staff as an assistant lecturer in 1929. His early papers dealt with Dirichlet series, analytic continuation, the divisor problem in residue classes and representations of a number as a sum of products. He died in London in 1991.