English

A refined 1-cocycle for regular isotopies and the refined tangle equations

Geometric Topology 2026-03-19 v2

Abstract

We refine the combinatorial 1-cocycle LRreg\mathbb{L}R_{reg} for regular isotopies of long knots to a 1-cocycle with values in the free Z[x,x1]\mathbb{Z}[x,x^{-1}]-module generated by regular isotopy classes of oriented tangles with exactly one signed ordinary double point. We use it to define the refined tangle equations for couples of knot diagrams, where the coefficients are now Laurent polynomials instead of integers. A solution of the tangle equations gives quantitative information about any knot isotopy which relates two given knot diagrams. If the tangle equations have no solution, then the diagrams represent different knots.

Keywords

Cite

@article{arxiv.2603.05640,
  title  = {A refined 1-cocycle for regular isotopies and the refined tangle equations},
  author = {Thomas Fiedler},
  journal= {arXiv preprint arXiv:2603.05640},
  year   = {2026}
}

Comments

30 pages, 22 figures, minore changes, reference added