Victor Puiseux

Victor Alexandre Puiseux (* April 16, 1820 in Argenteuil, † September 9, 1883 in Frontenay (Jura) ) was a French mathematician who has focused particularly on function theory and celestial mechanics.

Puiseux attended school in Pont-à- Mousson, and from 1834, the College Rollin in Paris, where he attended lectures by Charles -François Sturm. In 1837 he attended the École Normale Supérieure (ENS ), where he befriended and 1840 graduated with Charles Auguste Briot and Jean- Claude Bouquet as the best of his year. At that time he also attended lectures by Augustin Louis Cauchy. In 1841, he completed a doctorate on celestial mechanics. From 1841 to 1844 he was Professor of Mathematics in Rennes and from then until 1849 in Besançon. Meanwhile, he published papers on geometry and mechanics in Liouville's Journal. From 1849 to 1855 he was at the ENS, 1855-1859 at the Paris Observatory, and in 1857 he became professor of celestial mechanics after he had held a substitute, Urbain Le Verrier for lectures. From 1862 to 1868, he taught at the ENS. From 1868 to 1872 he was with the Bureau des Longitudes.

Puiseux improved in celestial mechanics, among others, the lunar theory of Laplace. But he is best known for his work in the theory of functions in connection to Cauchy, which was overshadowed in his lifetime by the work of Bernhard Riemann. According to him, power series expansions are named with fractional powers ( Puiseux developments). He was the first to branch points, essential singularities and poles difference.

In 1871 he was elected ( Académie des sciences ) in the Paris Academy of Sciences.

Puiseux was also an avid mountaineer. The main summit of Mont Pelvoux was probably climbed by him first and has since been called Pointe Puiseux ( 3,946 m).

His son Pierre Henri Puiseux (1855-1928) was a famous astronomer at the Paris Observatory, among other things, Was Mitersteller a photographic lunar atlas. A lunar crater is named after him (and not his father).