Hatcher-Algebraic-Topology · Problem 12

Homotopy Theory

Mathematics — Graph Theory · homotopy-equivalence-universal-cover-homology

Problem

Show that a map f:X→Yf: X \to Y of connected CW complexes is a homotopy equivalence if it induces an isomorphism on π1\pi_1 and if a lift f~:X~→Y~\tilde{f}: \tilde{X} \to \tilde{Y} to the universal covers induces an isomorphism on homology. [The latter condition can be restated in terms of homology with local coefficients as saying that f∗:H∗(X;Z[π1X])→H∗(Y;Z[π1Y])f_*: H_*(X; \mathbb{Z}[\pi_1 X]) \to H_*(Y; \mathbb{Z}[\pi_1 Y]) is an isomorphism; see §3.H.]

Related theory

Browse the problem library