Karl Fritiof Sundman

Karl Frithiof Sundman (28 October 1873, Kaskinen – 28 September 1949, Helsinki) was a Finnish mathematician who used analytic methods to prove the existence of a convergent infinite series solution to the three-body problem in 1906 and 1909. He also published a paper on regularization methods in mechanics in 1912. In the 1990s, Qiudong Wang generalized Sundman's solution to the case of more than three bodies.

Sundman was awarded the Pontécoulant prize by the French Academy of Science in 1913 for this work. In 1947, Sundman was elected a foreign member of the Royal Swedish Academy of Sciences. The crater Sundman on the Moon is named after him, as is the asteroid 1424 Sundmania.

...
Wikipedia