English

A note on Dehn colorings and invariant factors

Geometric Topology 2018-11-20 v2

Abstract

If AA is an abelian group and ϕ\phi is an integer, let A(ϕ)A(\phi) be the subgroup of AA consisting of elements aAa \in A such that ϕa=0\phi \cdot a=0. We prove that if DD is a diagram of a classical link LL and 0=ϕ0,ϕ1,,ϕn10=\phi_0,\phi_1,\dots,\phi_{n-1} are the invariant factors of an adjusted Goeritz matrix of DD, then the group DA(D)\mathcal{D}_{A}(D) of Dehn colorings of DD with values in AA is isomorphic to the direct product of AA and A=A(ϕ0),A(ϕ1),,A(ϕn1)A=A(\phi_{0}),A(\phi_1),\dots,A(\phi_{n-1}). It follows that the Dehn coloring groups of LL are isomorphic to those of a connected sum of torus links T(2,ϕ1) #  # T(2,ϕn1)T_{(2,\phi_1)} \text{ }\# \text{ } \cdots \text{ } \# \text{ } T_{(2,\phi_{n-1})}.

Keywords

Cite

@article{arxiv.1804.02700,
  title  = {A note on Dehn colorings and invariant factors},
  author = {Derek A. Smith and Lorenzo Traldi and William Watkins},
  journal= {arXiv preprint arXiv:1804.02700},
  year   = {2018}
}

Comments

v1: 10 pages, 4 figures. v2: 9 pages, 3 figures. Further changes may be made before publication in the Journal of Knot Theory and its Ramifications