Marius Sophus Lie
Lie, Marius Sophus
Born Dec. 17, 1842, in Nordfjordeide; died Feb. 18, 1899, in Christiania (Oslo). Norwegian mathematician.
In 1872, Lie was appointed a professor at the University of Christiania. From 1886 to 1898 he taught at the University of Leipzig. Lie founded the classical theory of continuous groups (called the theory of Lie groups), which was subsequently developed into a general theory of continuous groups. His first studies (1871–72) dealt with purely geometrical problems. However, by 1872 he had turned to the theory of differential equations and introduced into it the concepts and methods of n-dimensional geometry. The theory of Lie groups, which arose as a result of an attempt to introduce a common origin and to establish general viewpoints in various branches of mathematics, has exerted a profound influence on the subsequent development of the theory of differential equations, algebra, the foundations of geometry, topology, and theoretical physics. As a result of the studies of Lie and F. Klein, geometry has been reorganized on the basis of group-theoretic transformations.