approximate fibration;
codimension-2;
fibrator;
degree one mod 2 map;
mod 2 continuity set;
D O I:
10.1016/S0166-8641(97)00116-8
中图分类号:
O29 [应用数学];
学科分类号:
070104 ;
摘要:
A closed connected n-manifold N is called a codimension-2 fibrator (codimension-2 orientable fibrator, respectively) if each proper map p:M --> B on an (orientable, respectively) (n + 2)manifold M each fiber of which is shape equivalent to N is an approximate fibration. All Hopfian manifolds with Hopfian fundamental group and nonzero Euler characteristic are known to be codimension-2 orientable fibrators. This paper gives a partial answer the following question: is every closed manifold N with tau(1)(N) Hopfian and nonzero Euler characteristic chi(N) not equal 0 a codimension-2 fibrator? The main result states that, if chi(N) not equal 0 and tau(1)(N) is finite, then N is a codimension-2 fibrator. (C) 1998 Elsevier Science B.V.