BRANCHED COVERING SPACES AND THE QUADRATIC FORMS OF LINKS, II
BRANCHED COVERING SPACES AND THE QUADRATIC FORMS OF LINKS, II
复制标题
分支覆盖空间和链接的二次形式,II
DOI:
10.2307/1969717
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发表时间:
1954
影响因子:
4.9
通讯作者:
R. Fox
中科院分区:
文献类型:
--
作者:
R. Kyle;R. Fox
Self-linking in the homology groups of an oriented manifold was introduced by Seifert [12] and applied to the cyclic coverings of knots [13]. More or less complete systems of invariants of self-linking were defined by Seifert [12], Burger [2] and Blanchfield and Fox [1]. It was shown by Puppe [9], Kneser and Puppe [8], and Kyle [6] that the so-called quadratic form of a knot or link is determined by the self-linking in the homology groups of the second cyclic covering. It is the object of this paper to dualize this theory. The dualization of self-linking is carried out in ? 2; homology groups are replaced by cohomology groups and self-linking in the homology groups by a product operation -a in the cohomology groups. More precisely self-linking in the torsion subgroups of the homology groups is replaced by a dual operation in the torsion subgroups of the cohomology groups. The dualized theory is, of course, more general, in the sense that it applies to arbitrary complexes and not just to oriented manifolds. It is also more algebraic in nature. The calculations can be made from the incidence matrices of a regular cell-complex, and do not require the geometric determination of intersections. Calculation of --, makes use of a chain approximation to the diagonal map and is indicated in more detail for the case of special interest here, the case of a 3-dimensional manifold. The topological theory of branched covering spaces has been put on a solid foundation in [5], and in ? 3 results of [5] are put into a form suitable for the calculations to follow. In ? 4 a method for the calculation of in the cyclic branched coverings of a tame knot or link is given. In ? 5 it is shown that Seifert's results on the second cyclic branched covering can be deduced from this. 686