Algebraic Topology · Problem 26

Homotopy Theory — Allen Hatcher

Mathematics — Topology · isomorphic-homotopy-groups-not-homotopy-equivalent

Problem

Generalizing the example of RP2\mathbb{R}P^2 and S2×RP∞S^2 \times \mathbb{R}P^\infty, show that if XX is a connected finite-dimensional CW complex with universal cover X~\tilde{X}, then XX and X~×K(π1(X),1)\tilde{X} \times K(\pi_1(X), 1) have isomorphic homotopy groups but are not homotopy equivalent if π1(X)\pi_1(X) contains elements of finite order.

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