Fundamental Group & Covering Spaces Flashcards
deck transformation
homeomorphism φ from E to E such that pφ=p
universal cover
E is simply connected and there is covering map p from E to X
semi-locally simply connected
each point in X has a neighbourhood U with the property that any loop in U is based homotopic in X to the constant loop
Borsuk-Ulam Theorem
for any integers n>m>=0 there exists no continuous map φ from S^n to S^m which is antipode preserving
Ham Sandwich Theorem
Let X_1,…,X_n be bounded Lebesque measurable subsets of R^n. There exists a hyperplane bisecting each X_i simultaneously
continuous action
the map to the action is continuous
covering space action
continuous and every point in X has an open neighbourhood S such that gS intersect with S is empty for all non trivial g