Anders Lindstedt

Anders Lindstedt (* June 27 1854 in the Församling Sundborn, community Falun, † May 16, 1939 in Stockholm) was a Swedish mathematician and astronomer.

Lindstedt studied from 1872 at Lund University, where he received his doctorate in 1877 and thereafter was a lecturer in astronomy. During the study it was 1874/5 Observer at the Observatory in Hamburg. In 1879 he went for seven years as a lecturer at the then Russian University of Dorpat, where he worked with both theoretical (eg, three-body problem ) and observational astronomy. Initially he was Observer at the Observatory, from 1883 professor of mathematics. 1886 returned to Sweden, where he was Professor of Mathematics and Mechanics at the Royal Institute of Technology Stockholm. There he occupied himself especially with insurance mathematics as theory of pension funds and was partly state inspector for insurance. In 1909 he moved completely into the insurance business and became chairman of a committee that conducted the necessary for the Government Pension Fund in 1913 established statistical studies. 1909 to 1916 he was also Swedish Supreme Administrative Court and after the First World War, one of the international judges who governed the allocation of the State Social Insurance Fund between Germany, Poland and France after the Treaty of Versailles. 1917 to 1924 he was chairman of the arbitration committee for disability insurance in Sweden. In 1924 he retired, but remained active as an insurance scientists.

His work on celestial mechanics influenced Henri Poincaré. The Lindstedt - Poincaré method is named after them. It is used for uniform approximation of periodic solutions of ordinary differential equations in cases where the usual perturbation theory fails, and removes secular terms in the perturbation theory.

He was a corresponding member of the Institute of Actuaries in London.