Source: wikibot/lusternik-schnirelmann-category
= Lusternik–Schnirelmann category
{wiki=Lusternik–Schnirelmann_category}
The Lusternik–Schnirelmann (LS) category is a concept in algebraic topology that measures the "complexity" of a topological space in terms of how it can be covered by open sets that have some sort of "simple" structure, specifically, contractible sets.