Abstract
Let p : M → B be a proper surjective map defined on an (n + 2)-manifold such that each point-preimage is a copy of a hopfian n-manifold. Then we show that p is an approximate fibration over some dense open subset O of the mod 2 continuity set C′ and C′\O is locally finite. As an application, we show that a hopfian n-manifold N is a codimension-2 fibrator if χ(N) ≠ 0 or H1(N) ≅ ℤ2.
Original language | English |
---|---|
Pages (from-to) | 127-134 |
Number of pages | 8 |
Journal | Fundamenta Mathematicae |
Volume | 159 |
Issue number | 2 |
DOIs | |
State | Published - 1999 |
Keywords
- Approximate fibration
- Codimension-2 fibrator
- Continuity set
- Degree one mod 2 map
- Hopfian manifold
- Hyperhopfian group
- Strongly hopfian manifold