Knot theory and cluster algebras II: The knot cluster

Fuente: arXiv
Saved in:
Bibliographic Details
Main Authors: Bazier-Matte, Véronique, Schiffler, Ralf
Format: Preprint
Published: 2024
Subjects:
Online Access:
Tags: Add Tag
No Tags, Be the first to tag this record!
_version_ 1866914812900933632
author Bazier-Matte, Véronique
Schiffler, Ralf
author_facet Bazier-Matte, Véronique
Schiffler, Ralf
contents To every knot (or link) diagram K, we associate a cluster algebra A that contains a cluster x with the property that every cluster variable in x specializes to the Alexander polynomial of K. We call x the knot cluster of A. Furthermore, there exists a cluster automorphism of A of order two that maps the initial cluster to the cluster x. We realize this connection between knot theory and cluster algebras in two ways. In our previous work, we constructed indecomposable representations T(i) of the initial quiver Q of the cluster algebra A. Modulo the removal of 2-cycles, the quiver Q is the incidence quiver of the segments in K, and the representation T(i) of Q is built by taking successive boundaries of K cut open at the i-th segment. The relation to the Alexander polynomial stems from an isomorphism between the submodule lattice of T(i) and the lattice of Kauffman states of K relative to segment i. In the current article, we identify the knot cluster x in A via a sequence of mutations that we construct from a sequence of bigon reductions and generalized Reidemeister III moves on the diagram K. On the level of diagrams, this sequence first reduces K to the Hopf link, then reflects the Hopf link to its mirror image, and finally rebuilds (the mirror image of) K by reversing the reduction. We show that every diagram of a prime link admits such a sequence. We further prove that the cluster variables in x have the same F-polynomials as the representations T(i). This establishes the important fact that our representations T(i) do indeed correspond to cluster variables in A. But it even establishes the much stronger result that these cluster variables are all compatible, in the sense that they form a cluster. We also prove that the representations T(i) have the following symmetry property. For all vertices i,j of Q, the dimension of T(i) at j is equal to the dimension of T(j) at i.
format Preprint
id arxiv_https___arxiv_org_abs_2405_16592
institution arXiv
publishDate 2024
record_format arxiv
spellingShingle Knot theory and cluster algebras II: The knot cluster
Bazier-Matte, Véronique
Schiffler, Ralf
Combinatorics
General Topology
Representation Theory
13F60, 57K14, 16G20
To every knot (or link) diagram K, we associate a cluster algebra A that contains a cluster x with the property that every cluster variable in x specializes to the Alexander polynomial of K. We call x the knot cluster of A. Furthermore, there exists a cluster automorphism of A of order two that maps the initial cluster to the cluster x. We realize this connection between knot theory and cluster algebras in two ways. In our previous work, we constructed indecomposable representations T(i) of the initial quiver Q of the cluster algebra A. Modulo the removal of 2-cycles, the quiver Q is the incidence quiver of the segments in K, and the representation T(i) of Q is built by taking successive boundaries of K cut open at the i-th segment. The relation to the Alexander polynomial stems from an isomorphism between the submodule lattice of T(i) and the lattice of Kauffman states of K relative to segment i. In the current article, we identify the knot cluster x in A via a sequence of mutations that we construct from a sequence of bigon reductions and generalized Reidemeister III moves on the diagram K. On the level of diagrams, this sequence first reduces K to the Hopf link, then reflects the Hopf link to its mirror image, and finally rebuilds (the mirror image of) K by reversing the reduction. We show that every diagram of a prime link admits such a sequence. We further prove that the cluster variables in x have the same F-polynomials as the representations T(i). This establishes the important fact that our representations T(i) do indeed correspond to cluster variables in A. But it even establishes the much stronger result that these cluster variables are all compatible, in the sense that they form a cluster. We also prove that the representations T(i) have the following symmetry property. For all vertices i,j of Q, the dimension of T(i) at j is equal to the dimension of T(j) at i.
title Knot theory and cluster algebras II: The knot cluster
topic Combinatorics
General Topology
Representation Theory
13F60, 57K14, 16G20
url https://arxiv.org/abs/2405.16592