Stieltjes, Thomas Jan (1856–1894)

Dutch-born French mathematician who contributed greatly to the theory of series and is often called the founder of analytical theory. His analysis of continued fractions, in particular, has had immense influence in the development of mathematics.

Stieltjes was born in Zwolle and studied at the polytechnic in Delft. He worked at the Leiden Observatory 1877–83. In 1884 he became professor of mathematics at Groningen. From 1886 he taught at the University of Toulouse, France.

Stieltjes studied almost all the problems in analysis then known – the theory of ordinary and partial differential equations, Euler's gamma functions, elliptic functions, interpolation theory, and asymptotic series. His researches also raised the mathematical status of discontinuous functions and divergent series.

His memoir ‘Recherches sur les fractions continues’, completed just before he died and published in two parts (1894 and 1895), was a milestone in mathematical history. Stieltjes was the first mathematician to give a general treatment of continued fractions as part of complex analytical function theory.