2‐torsion in the n‐solvable filtration of the knot concordance group
2‐torsion in the n‐solvable filtration of the knot concordance group
复制标题
结索引组的 n 可解过滤中的 2-扭转
DOI:
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发表时间:
2009
期刊:
影响因子:
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通讯作者:
Constance Leidy
中科院分区:
文献类型:
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作者:
Tim D. Cochran;Shelly L. Harvey;Constance Leidy
Cochran–Orr–Teichner introduced in [‘Knot concordance, Whitney towers and L2‐signatures’, Ann. of Math. (2) 157 (2003) 433–519] a natural filtration of the smooth knot concordance group C …⊂Fn+1⊂Fn.5⊂Fn⊂…⊂F1⊂F0.5⊂F0⊂C, called the (n)‐solvable filtration. We show that each associated graded abelian group { Gn=Fn/Fn.5|n∈N },n⩾2 , n ⩾ 2, contains infinite linearly independent sets of elements of order 2 (this was known previously for n = 0, 1). Each of the representative knots is negative amphichiral, with vanishing s‐invariant, τ‐invariant, δ‐invariants and Casson–Gordon invariants. Moreover, each is slice in a rational homology 4‐ball. In fact we show that there are many distinct such classes in Gn , distinguished by their Alexander polynomials and, more generally, by the torsion in their higher‐order Alexander modules.