Torsten Carleman

Days Gills Torsten Carleman ( born July 8, 1892 in Visseltofta, Osby Municipality, † January 11, 1949 in Stockholm ) was one of Sweden's leading mathematicians of the 20th century.

Life

Carleman studied mathematics at Uppsala University, where he also received his doctorate in 1917 with Erik Holmgren (On the Neumann - Poincaré problem for a region with corners ) and then a lecturer. After several stays abroad he received in 1923 a professorship at the University of Lund, but followed a year later as the successor of Helge von Koch at the University of Stockholm. 1927 was appointed after the death of Magnus Gösta Mittag-Leffler as the first director of the newly founded Mittag-Leffler Institute. Carleman was considered the leading Swedish mathematician, however, the institute could not help to shine, so that it consisted mainly of a collated nor of Mittag-Leffler well-equipped library.

Carle man proved important statements to singular integral equations. In particular, he examined on integral operators whose kernel satisfies the conditions for almost all and for almost all. Such nuclei are called Carleman kernels today. Based on previous results of Arnaud Denjoy, he gave a characterization of quasi- analytic functions, which is known as a set of Denjoy and Carleman today. In the proof he used a now known as Carleman inequality inequality. The set of Denjoy - Carleman - Ahlfors deals with a completely different theme than the set of Denjoy and Carleman: It says that an entire function of finite order has a maximum asymptotic values ​​. Denjoy had proved this for a special case and suggested that this generally applies. Carleman could of show before then Denjoys Ahlfors conjecture fully proved this with the place. Shortly after Carleman was another proof. Another functional theoretical result is the Carleman -Jensen formula, which can be regarded as an analogue of Jensen's formula for the semi-circle. Carleman used this formula to prove the analogue of the set of Müntz on approximation by powers of analytic functions. Additional results of Carleman deal with, among others, ergodic theory, partial differential equations and mathematical physics, where he proved an existence theorem for the Boltzmann equation.

In 1932 he gave a plenary lecture at the International Congress of Mathematicians in Zurich (On the theory of linear integral equations and their applications, held in French).

His doctoral Åke heard Pleijel.