Using Fibonacci Numbers and Chebyshev Polynomials to Express Fox Coloring Groups and Alexander-Burau-Fox Modules of Diagrams of Wheel Graphs
Anthony Christiana, Huizheng Guo, Jozef H. Przytycki
TL;DR
The paper derives closed formulas for the reduced Fox coloring groups of wheel-graph diagrams, showing Col^{red}(D_n) is determined by Fibonacci numbers and Lucas numbers via wheel-graph combinatorics. It then generalizes to the Alexander-Burau-Fox module over $\mathbb{Z}[t^{\pm1}]$ using Chebyshev polynomials of the second kind, providing an explicit module decomposition into cyclic summands and computing the determinant of a reduced ABF matrix. The work illuminates a deep connection between colorings, Chebyshev polynomials, and Burau representation, linking knot-theoretic invariants to branched-covering topology through product-to-sum identities and explicit matrix reductions. Overall, the results yield compact, computable formulas for both the reduced coloring groups and ABF modules for the class of closures of $(\sigma_1\sigma_2^{-1})^n$, with potential implications for branched-covering homology and orderability questions in 3-manifold topology.
Abstract
In this paper we compute the Reduced Fox Coloring Group of the diagrams of Wheel Graphs which can also be represented at the closure of the braids $(σ_1 σ_2^{-1})^n$. In doing so, we utilize Fibonacci numbers and their properties. Following this, we generalize our result to compute the Alexander-Burau-Fox Module over the ring $\mathbb{Z}[t^{\pm 1}]$ for the same class of links. In our computation, Chebyshev polynomials function as a generalization of Fibonacci Numbers.
