In various paper i found this:
But i don't find this theorem of Lusternik-Schnirelmann, have you an idea where i can find this theorem, the condition?
Thank you.
In various paper i found this:
But i don't find this theorem of Lusternik-Schnirelmann, have you an idea where i can find this theorem, the condition?
Thank you.
You might want to check the paper
Palais, Richard S. Lusternik-Schnirelman theory on Banach manifolds. Topology 5 1966 115–132.
See also Theorem 1.15 of
Cornea, Octav; Lupton, Gregory; Oprea, John; Tanré, Daniel Lusternik-Schnirelmann category. Mathematical Surveys and Monographs, 103. American Mathematical Society, Providence, RI, 2003.
The relevant chapter is available to view on Google Books.