Henri Poincaré
1854-1912

Born in Nancy, France. Degree from the École Polytechique, Paris, 1879. Professor at Caen, 1879-1881, University of Paris, 1881 on. Primarily interested in analysis, applications of analysis and topology in theoretical physics. Studied uniformization of analytic functions using automorphic functions, developed first steps in algebraic topology, introduced the fundamental topological group ₁ .

Discovered the integral invariants of Hamiltonian systems, 1890. Analyzed stability of motion, introduced Lyapunov-Poincaré exponents, 1890. Published 3 volume Mécanique céleste, 1892-99. Introduced topological methods, mappings, in the analysis of problems in dynamics, used to prove the Poincaré recurrence theorem. Demonstrated that there are no independent algebraic constants of the motion in the restricted 3-body problem other than H and L ("Bruns-Poincaré theorem"). Developed theory of asymptotic series in connection with dynamical problems, celestial mechanics. Introduced the Poincaré group of transformations of relativistic particles.