The Lusternik-Schnirelmann theory has been originated in 1930th, and last decade it meets a renaissance. The contemporary level of the theory relates topology, analysis, geometry, complexity theory and other interesting subjects. In the talk I want to recall the main points of the development of the theory, as well as to show recent results and applications.
Links:
[1] http://www.mpim-bonn.mpg.de/taxonomy/term/39
[2] http://www.mpim-bonn.mpg.de/node/3444
[3] http://www.mpim-bonn.mpg.de/node/249