Necessary and sufficient conditions for s-Hopfian manifolds to be codimension-2 fibrators.

Fibrators help detect approximate fibrations. A closed, connected $n$-manifold $N$ is called a codimension-2 fibrator if each map $p: M \to B$ defined on an $(n+2)$-manifold $M$ such that all fibre $p^{-1}(b), b\in B$, are shape equivalent to $N$ is an approximate fibration. The most natural objects $N$ to study are s-Hopfian manifolds. In this note we give some necessary and sufficient conditions for s-Hopfian manifolds to be codimension-2 fibrators. [ABSTRACT FROM AUTHOR]