X-Nico

Estermann

Theodor Estermann (1902–1991), mathematician, working in analytic number theory

Hans Rademacher

Rademacher had a number of well known students, including George Andrews, Paul T. Bateman, Theodor Estermann and Emil Grosswald.

Rouché's theorem

Theodor Estermann (1902–1991) proved in his book Complex Numbers and Functions the following relation: Let $K\backslash subset\; G$ be a bounded region with continuous boundary $\backslash partial\; K$.

see also