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Perturbative Knot Invariants via Quantum Cluster Algebras

Boudewijn Bosch

Abstract

A perturbative expansion of knot invariants is derived using quantum cluster algebras. By interpreting the $R$-matrix of $U_q(\mathfrak{sl}_2)$ as a cluster transformation and introducing an auxiliary parameter $ε$, we derive a perturbed $R$-matrix expressed in terms of Heisenberg algebra generators arising from the representation theory of the quantum cluster algebra. The resulting knot invariant has a zeroth-order term equal to $Δ_K(T)^{-1}$, the reciprocal of the Alexander polynomial, while higher-order terms in $ε$ produce perturbed Alexander polynomials. The construction combines the Schrödinger representation of the quantum torus algebra with cluster mutation combinatorics and is illustrated with a \textit{Mathematica} implementation and explicit examples.

Perturbative Knot Invariants via Quantum Cluster Algebras

Abstract

A perturbative expansion of knot invariants is derived using quantum cluster algebras. By interpreting the -matrix of as a cluster transformation and introducing an auxiliary parameter , we derive a perturbed -matrix expressed in terms of Heisenberg algebra generators arising from the representation theory of the quantum cluster algebra. The resulting knot invariant has a zeroth-order term equal to , the reciprocal of the Alexander polynomial, while higher-order terms in produce perturbed Alexander polynomials. The construction combines the Schrödinger representation of the quantum torus algebra with cluster mutation combinatorics and is illustrated with a \textit{Mathematica} implementation and explicit examples.
Paper Structure (12 sections, 9 theorems, 59 equations, 3 figures)

This paper contains 12 sections, 9 theorems, 59 equations, 3 figures.

Key Result

Theorem 1.1

For a suitable cluster algebra with a distinguished choice of cluster variables, the mutation sequence associated with a triangulation of the complement of a knot $\mathcal{K}$ recovers the Alexander polynomial of $\mathcal{K}$ at the classical level; and after quantization and $\epsilon$-expansion,

Figures (3)

  • Figure 1: A quiver mutation in the direction $b$.
  • Figure 2: A triangulation of a 2-punctured disk
  • Figure 3: Half Dehn-twist for the 2-punctured disk.

Theorems & Definitions (18)

  • Theorem 1.1
  • Theorem 2.1: Stone--Von Neumann theorem
  • Definition 3.1
  • Definition 3.2
  • Lemma 3.4
  • Proposition 3.5
  • Proposition 3.6
  • Proposition 3.9
  • Proposition 3.10
  • Theorem 3.11
  • ...and 8 more