Reidemeister torsion and the laplacian on lens spaces
Reidemeister torsion and the laplacian on lens spaces
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雷德迈斯特挠率和透镜空间上的拉普拉斯
DOI:
10.1016/0001-8708(70)90018-6
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发表时间:
1970
期刊:
影响因子:
--
通讯作者:
D. Ray
中科院分区:
文献类型:
--
作者:
D. Ray
Let g be a rotation of a sphere &-r of odd dimension 33, such that, for some integer p 3 3, gp is the identity, while g” has no fix points for 0< K< p. Identification of the points of S,,-, under the action of g produces the lens space L,,-,(g). Since the betti numbers of L,,-,(g) do not depend on the rotation g, the lens spaces make good examples in studying the topologic classification of manifolds. The classification of lens spaces was accomplished in 1935 ([2]) by the introduction of the Reidemeister torsion. Roughly speaking, the torsion of a complex K is obtained by embedding K as a fundamental domain in the universal covering complex R. The boundary in K of a cell e of K is then given by a combination of translates ge’of cells of K by deck transformations. Thinking of the cells of K as a preferred base, this gives rise to a boundary matrix whose entries lie in the group ring of the fundamental group G.Each homomorphism of the group G into the complex numbers of modulus one transforms the boundary matrix into a complex matrix. One then looks for invariants of these boundary matrices under subdivision and under transformation by topologically permissible change of base. Franz ([2]) f ound that there was just one invariant, the torsion, besides the betti numbers. He used the torsion to prove that two lens spaces which are combinatorially equivalent are actually isometric, so that the rotations defining them are conjugate. The torsion is defined by a formula involving certain determinants constructed from the boundary matrices. In view of de Rham’s theorem relating the combinatorial cohomology of a closed oriented manifold to the cohomology of differential forms, the question arises of whether there is an analogous formula involving the exterior differential for forms.