- Born:
- Aug. 14, 1842, NĂźmes, France
- Died:
- Feb. 23, 1917, Paris (aged 74)
Jean-Gaston Darboux
Jean-Gaston Darboux (born Aug. 14, 1842, NĂźmes, Franceâdied Feb. 23, 1917, Paris) was a French mathematician who made important contributions to geometry and analysis and after whom the Darboux integral is named.
After acting as an assistant in mathematical physics (1866â67) at the CollĂšge de France, Paris, Darboux taught at the LycĂ©e Louis le Grand (1867â72), the Ăcole Normale SupĂ©rieure (1872â73), and the Sorbonne (1873â90). Besides being an excellent teacher and a notable mathematician, he was a very capable administrator.
Practically all Darbouxâs mathematical work was in geometry. His early papers (1864 and 1866) on orthogonal surfaces were followed by a memoir (1870) on partial-differential equations of the second order, which embodied a new method of integration. In his treatise Sur une classe remarquable de courbes et de surfaces algĂ©briques et sur la thĂ©orie des imaginaires (1873; âOn a Class of Remarkable Curves and Algebraic Surfaces and on the Theory of Imaginary Numbersâ), he developed the theory of the class of surfaces called cyclides.
Leçons sur la thĂ©orie gĂ©nĂ©rale des surfaces et les applications gĂ©omĂ©triques du calcul infinitĂ©simal, 4 vol. (1887â96; âLessons on the General Theory of Surfaces and the Geometric Applications of Infinitesimal Calculusâ), one of his most important works, deals with infinitesimal geometry and embodies most of his previous research work. In 1898 the publication of Leçons sur les systĂšmes orthogonaux et les coordonnĂ©es curvilignes (âLessons on Orthogonal Systems and Curvilinear Coordinatesâ) was begun. He was the author of a number of papers and memoirs on the approximation to functions of very large numbers, discontinuous functions, dynamics, and other mathematical subjects.