English

Universal cocycle Invariants for singular knots and links

Geometric Topology 2019-10-10 v1

Abstract

Given a biquandle (X,S)(X, S), a function τ\tau with certain compatibility and a pair of {\em non commutative cocyles} f,h:X×XGf,h:X \times X\to G with values in a non necessarily commutative group GG, we give an invariant for singular knots / links. Given (X,S,τ)(X,S,\tau), we also define a universal group Uncfh(X)U_{nc}^{fh}(X) and universal functions governing all 2-cocycles in XX, and exhibit examples of computations. When the target group is abelian, a notion of {\em abelian cocycle pair} is given and the "state sum" is defined for singular knots/links. Computations generalizing linking number for singular knots are given. As for virtual knots, a "self-linking number" may be defined for singular knots

Keywords

Cite

@article{arxiv.1910.04042,
  title  = {Universal cocycle Invariants for singular knots and links},
  author = {Marco Farinati and Juliana García Galofre},
  journal= {arXiv preprint arXiv:1910.04042},
  year   = {2019}
}

Comments

27 pages, 9 figures

R2 v1 2026-06-23T11:38:47.304Z