On the homotopy of closed manifolds and finite CW-complexes

Abstract

We study the finite generation of homotopy groups of closed manifolds and finite CW-complexes by relating it to the cohomology of their fundamental groups. Our main theorems are as follows: when $X$ is a finite CW-complex of dimension $n$ and ${\pi }_1(X)$ is virtually a Poincaré duality group of dimension $\ge n-1$, then ${\pi }_i(X)$ is not finitely generated for some $i$ unless $X$ is homotopy equivalent to the Eilenberg--MacLane space $K({\pi }_1(X),1)$; when $M$ is an $n$-dimensional closed manifold and ${\pi }_1(M)$ is virtually a Poincaré duality group of dimension $\ge n-1$, then for some $i\le [n/2]$, ${\pi }_i(M)$ is not finitely generated, unless $M$ itself is an aspherical manifold. These generalize theorems of M. Damian from polycyclic groups to any virtually Poincaré duality groups. When ${\pi }_1(X)$ is not a virtually Poincaré duality group, we also obtained similar results. As a by-product we showed that if a group $G$ is of type F and $H^i(G,\mathbb{Z}G)$ is finitely generated for any $i$, then $G$ is a Poincaré duality group. This recovers partially a theorem of Farrell.

13 pages. Add remarks about the work of C. Stark in the introduction, some other small changes. Comments welcome