English

An explicit computation of the Blanchfield pairing for arbitrary links

Geometric Topology 2020-12-30 v3

Abstract

Given a link LL, the Blanchfield pairing Bl(L)\operatorname{Bl}(L) is a pairing which is defined on the torsion submodule of the Alexander module of LL. In some particular cases, namely if LL is a boundary link or if the Alexander module of LL is torsion, Bl(L)\operatorname{Bl}(L) can be computed explicitly; however no formula is known in general. In this article, we compute the Blanchfield pairing of any link, generalizing the aforementioned results. As a corollary, we obtain a new proof that the Blanchfield pairing is hermitian. Finally, we also obtain short proofs of several properties of Bl(L)\operatorname{Bl}(L).

Keywords

Cite

@article{arxiv.1706.00226,
  title  = {An explicit computation of the Blanchfield pairing for arbitrary links},
  author = {Anthony Conway},
  journal= {arXiv preprint arXiv:1706.00226},
  year   = {2020}
}

Comments

23 pages, 1 figure. v2: Corollary 1.2 has been weakened; an appendix containing the proof of Lemma 3.1 has been added; other minor changes. To appear in the Canadian Journal of Mathematics. v3: The definition of the pairing $\lambda_H$ has been corrected