• 대한수학회보
• /
• 제35권3호
• /
• pp.491-501
• /
• 1998

If N is any cartesian product of a closed simply connected n-manifold $N_1$ and a closed aspherical m-manifold $N_2$, then N is a codimension 2 fibrator. Moreover, if N is any closed hopfian PL n-manifold with $\pi_iN=0$ for $2 {\leq} i < m$, which is a codimension 2 fibrator, and $\pi_i N$ is normally cohopfian and has no proper normal subroup isomorphic to $\pi_1 N/A$ where A is an abelian normal subgroup of $\pi_1 N$, then N is a codimension m PL fibrator.

• 대한수학회보
• /
• 제36권1호
• /
• pp.79-90
• /
• 1999

In this paper, we show that any product of a closed orientable n-manifold $N_1$ with finite fundamental group and a closed orientable asgerical m-mainfold $N_2$ with hopfian fundamental group, where X($N_1$) and X($N_2$) are nonzero, is a condimension 2 fibrator. Moreover, if <$\pi_i(N_1)$=0 for 1$N_1\timesN_2$ is a codimension k PL fibrator.

• 대한수학회논문집
• /
• 제25권2호
• /
• pp.283-289
• /
• 2010

Approximate fibrations provide a useful class of maps. Fibrators give instant detection of maps in this class, and PL fibrators do the same in the PL category. We show that rational homology spheres with some additional conditions are codimension-k PL fibrators and PL manifolds with trivial homology groups in some range can be codimension-k (k > 2) PL fibrators.

• 대한수학회논문집
• /
• 제22권2호
• /
• pp.289-295
• /
• 2007

We describe some conditions under which the product of two groups with certain property is a group with the same property, and we describe some conditions under which the product of hopfian manifolds is another hopfian manifold. As applications, we find some PL fibrators among the product of fibrators.

• 대한수학회지
• /
• 제43권1호
• /
• pp.99-109
• /
• 2006

Approximate fibrations form a useful class of maps. By definition fibrators provide instant detection of maps in this class, and PL fibrators do the same in the PL category. We show that every closed s-hopfian t-aspherical manifold N with sparsely Abelian, hopfian fundamental group and X(N) $\neq$ 0 is a codimension-(t + 1) PL fibrator.

• 대한수학회보
• /
• 제43권4호
• /
• pp.841-846
• /
• 2006

Suppose that F is a closed t-aspherical PL n-manifold with finite, sparsely abelian ${\pi}_1(F)$ and A is a closed aspherical PL m-manifold with hopfian, normally cohopfian ${\pi}_1(A)$. If $X(F){\neq}0{\neq}X(A)$, then $F{\times}A$ is a codimension-(t+1) PL fibrator.

• 호남수학학술지
• /
• 제29권3호
• /
• pp.327-339
• /
• 2007

Approximate fibrations form a useful class of maps. By definition fibrators provide instant detection of maps in this class, and PL fibrators do the same in the PL category. We show that every closed s-hopfian t-aspherical manifold N with some algebraic conditions and X(N) $\neq$ 0 is a codimension-(2t + 2) PL fibrator.