Henri Poincaré
1854–1912, Nancy, Lorraine, France, Paris, France
French mathematician and physicist, often called the last universalist, who founded algebraic topology and the qualitative theory of dynamical systems, discovered chaotic behaviour in the three-body problem, and posed the Poincaré conjecture.
Poincaré excelled at every subject at the Lycée in Nancy (later renamed in his honour) and graduated top of his class from the École Polytechnique in 1875. He received his doctorate from the University of Paris in 1879 under Charles Hermite for work on differential equations, and from 1886 held chairs in mathematical physics, probability and celestial mechanics at the Sorbonne and the École Polytechnique, where he remained for the rest of his career.
In 1889, after submitting a memoir for King Oscar II of Sweden's three-body-problem prize competition, Poincaré discovered an error in the prize-winning memoir while it was being prepared for publication; correcting it led him to the first description of homoclinic points and chaotic dynamics, an event now seen as the birth of chaos theory. His 1895 work Analysis situs founded algebraic topology, introducing the fundamental group, and in 1904 he posed the Poincaré conjecture on the characterisation of the 3-sphere, which remained open until Grigori Perelman's proof in 2002–2003. He made important contributions to the foundations of special relativity, alongside the work of Lorentz and Einstein. He died suddenly in Paris in 1912 after surgery.
Workplaces: University of Paris (Sorbonne), École Polytechnique, Paris
France