Communications of the
Korean Mathematical Society CKMS

Let $N$ be a closed $n$-manifold with residually finite, torsion free $\pi_1(N)$ and finite $H_1(N)$. Suppose that $\pi_k(N)=0$ for $1 < k < n-1$. We show that $N$ is a codimension-$n$ PL fibrator if and only if $N$ does not cover itself regularly and cyclically up to homotopy type, provided $\pi_1(N)$ satisfies a certain condition.

Keywords: residually finite group, hopfian manifold, approximate fibration

MSC numbers: Primary 57N15, 55M25; Secondary 57M10, 54B15