1809 – 1882
Joseph Liouville (1809–1882) was a French mathematician whose work spanned analysis, number theory, and mathematical physics. He is best known for Liouville's theorem in Hamiltonian mechanics, which establishes the conservation of phase-space volume, and for founding the influential Journal de Mathématiques Pures et Appliquées. His contributions to mathematical physics provided foundational tools later applied in thermodynamics and statistical mechanics.
Proved Liouville's theorem: phase-space volume is conserved under Hamiltonian flow
Demonstrated the existence of transcendental numbers by constructing Liouville numbers
Founded and edited the Journal de Mathématiques Pures et Appliquées (1836)
Developed Sturm-Liouville theory for eigenvalue problems in differential equations
Made early contributions to fractional calculus and complex analysis