Gerrit Lekkerkerker

Lekkerkerker studied mathematics at Utrecht University during the periods 1940-1943 and 1945-1949 under Jurjen Koksma and Jan Popken.

[1] In 1955 he received his doctorate under the guidance of Popken with the thesis On the Zeros of a Class of Dirichlet-Series; in Dutch: Over de nulpunten in een klasse van Dirichletreeksen.

In 1984, although he had not yet reached retirement age, he resigned his professorship over differences in the teaching of mathematical analysis, feeling that his academic freedom was under threat.

Afterwards he worked with Rutger Hangelbroek, who did his doctorate under Lekkerkerker in 1973 at the University of Groningen, and Hans Kaper of the Argonne National Laboratory.

[1] After retiring, he remained active in mathematics: for example, he brought out a second edition of Geometry of Numbers along with Peter Grüber.