On quadratic forms of 3-manifolds
On quadratic forms of 3-manifolds
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关于 3-流形的二次形式
DOI:
10.1007/bf01390003
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发表时间:
1977
影响因子:
3.1
通讯作者:
A. Kawauchi
中科院分区:
文献类型:
--
作者:
A. Kawauchi
JW Milnor [16] defined a quadratic form of the knot exterior (ie, the closed knot complement) E (k) of a classical tame knot kc S 3 associated with a generator of H 1 (E (k); Z) that is specified by the orientations of the knot k and the containing 3-sphere S a. The quadratic form of the knot exterior is necessarily nonsingular and it was applied for the Fox-Milnor knot cobordism group [5]. The author defined analogously non-singular quadratic forms for closed 3-manifolds having the integral homology groups of an orientable handle S 1 x S 2 and this quadratic form was applied for the/~-cobordism group~(S 1 x S 2) of the homology orientable handles.(See [11].)The main purpose of this paper is to define quadratic forms for arbitrary, compact, connected and oriented 3-manifolds with non-zero first Betti numbers and to deduce basic properties of the forms. In order to define the quadratic form, we will need a generalization of the Milnor duality theorem [16], which may be also regarded as a version of the Blanchfield duality theorem [1] on the infinite cyclic covers of manifolds. Our quadratic form will be, in many cases, singular and, as in the link theory [7, 17, 18] etc., we will define the (one variable) Alexander polynomial, the Hosokawa polynomial, the Murasugi signature and the nullity. The Alexander polynomial and the Hosokawa polynomial will be defined so as to be always non-zero polynomials. Accordingly, our definition of the Alexander (or Hosokawa) polynomial will be strictly distinct from the original definition, but if it is not zero, then the original Alexander (or Hosokawa) polynomial will be equal to our Alexander (or Hosokawa) polynomial. The concepts of the Murasugi signature and the nullity of the form will be distinct from the original concepts of [17]. The quadratic forms and hence these invariants will be seen to be closely related to the various (restricted) cobordism problems of 3-manifolds. The paper contains concrete three applications. The first will give a polynomial condition for a certain finitely presented group to be a 3-manifold group. For example, we shall show that the Baumslag-Solitar group G~ vq~=