Moves for Flow-Spines and Topological Invariants of 3-Manifolds
Moves for Flow-Spines and Topological Invariants of 3-Manifolds
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流脊柱的移动和 3 流形的拓扑不变量
DOI:
10.3836/tjm/1270129457
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发表时间:
1992
影响因子:
0.6
通讯作者:
I. Ishii
中科院分区:
文献类型:
--
作者:
I. Ishii
A spine $P$ for a closed 3-manifold $M$ is a 2-dimensional polyhedron in $M$ such that the complement of the regular neighborhood of $P$ is homeomorphic to the 3-ball. Cutting off a closed 3-manifold $M$ along its spine $P$, we get a 3-ball $B^{3}$ with an identification on its boundary. This is a polyhedral representation of $M$, which is first considered by M. Dehn in the case of closed surfaces, and introduced by H. Seifert in the 3-dimensional case. A DS-diagram is a polyhedral representation of a special class, which was first introduced in [3]. A spine corresponding to a DS-diagram forms a closed fake surface (cf. [1], [3]). A spine which forms a closed fake surface is called a standard or a simple spine. As is pointed out in [12], a standard spine is the dual ofa singular triangulation. A flow-spine introduced in [7] is a standard spine of a more special class, which is generated by a pair of a non-singular flow and its local section. It was shown in [4] and [7] that a DS-diagram for a flow-spine has an E-cycle. An E-cycle is a cycle of the graph of a DS-diagram which represents a kind of symmetry of a polyhedral representation. (See \S 1 for precise.) A closed 3-manifold admits infinitely many flow-spines. In this paper, we shall give conditions for two flow-spines to represent the same manifold, that is, it will be shown that any two flow-spines of a 3-manifold can be transformed from one to another by a finite sequence of operations of three types which we call “moves”. A flow-spine is completely determined by a data on the E-cycle, which will be called an E-data (cf. \S 1). An E-data is the one called a singularity-data in [7]. Our moves of flow-spines are described in terms of E-data. For an easy description of moves of E-data, we introduce the graphic representation of an E-data in \S 1. An E-data determines not only a 3-manifold $M$ but also a class of non-singular flows on $M$ (see \S 1). Moves of E-data are divided into two types, moves which do not change the class of non-singular flows and those which change the class. Moves of the first type are called regular moves and discussed in \S 2. The second type consists of only