B4.5

Algebraic Topology
Part II, 2004

Write down the definition of a covering space and a covering map. State and prove the path lifting property for covering spaces and state, without proof, the homotopy lifting property.

Suppose that a group GG is a group of homeomorphisms of a space XX. Prove that, under conditions to be stated, the quotient map XX/GX \rightarrow X / G is a covering map and that π1(X/G)\pi_{1}(X / G) is isomorphic to GG. Give two examples in which this last result can be used to determine the fundamental group of a space.