Êtes-vous un étudiant de l'EPFL à la recherche d'un projet de semestre?
Travaillez avec nous sur des projets en science des données et en visualisation, et déployez votre projet sous forme d'application sur Graph Search.
Concept
Compact convergence
Résumé
In mathematics compact convergence (or uniform convergence on compact sets) is a type of convergence that generalizes the idea of uniform convergence. It is associated with the compact-open topology.
Let be a topological space and be a metric space. A sequence of functions
is said to converge compactly as to some function if, for every compact set ,
uniformly on as . This means that for all compact ,
If and with their usual topologies, with , then converges compactly to the constant function with value 0, but not uniformly.
If , and , then converges pointwise to the function that is zero on and one at , but the sequence does not converge compactly.
A very powerful tool for showing compact convergence is the Arzelà–Ascoli theorem. There are several versions of this theorem, roughly speaking it states that every sequence of equicontinuous and uniformly bounded maps has a subsequence that converges compactly to some continuous map.
If uniformly, then compactly.
If is a compact space and compactly, then uniformly.
If is a locally compact space, then compactly if and only if locally uniformly.
If is a compactly generated space, compactly, and each is continuous, then is continuous.
Source officielle
À propos de ce résultat
Cette page est générée automatiquement et peut contenir des informations qui ne sont pas correctes, complètes, à jour ou pertinentes par rapport à votre recherche. Il en va de même pour toutes les autres pages de ce site. Veillez à vérifier les informations auprès des sources officielles de l'EPFL.