Simply Connected Finite CW-Complex – Homotopy and Homology Groups

at.algebraic-topologygt.geometric-topology

Let $X$ be a simply connected finite CW-complex such that all but finitely many of its homotopy groups and its homology groups (with $\mathbb Z$ coefficients) are 0.

Is $X$ then necessarily contractible?

I do not really believe that this is true; but I was also not able to construct a counterexample.

Best Answer

By results of J.P. Serre (for $p=2$) and Y. Umeda (for odd $p$) we know that a 1-connected finite CW-complex $X$ with non-trivial cohomology mod $p$ has infinitely many non-trivial homotopy groups mod $p$.

In fact C.A. McGibbon and J.A. Neisendorfer have proved the existence of $p$-torsion elements in infinitely many dimensions for finite dimensional spaces using H. Miller's theorem on the Sullivan conjecture.

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