Explicit formulae for the Aicardi-Juyumaya bracket of tied links
O'Bryan Cárdenas-Andaur, Juan González-Meneses, Marithania Silvero
TL;DR
This work delivers the first closed-form state-sum expressions for the Aicardi-Juyumaya bracket on tied links by a careful, case-by-case analysis of AJ-states in 2- and 3-tied diagrams. The authors deploy resolution trees and a meticulous accounting of passable leaf types to derive explicit formulas that express $\\langle\\langle D \\\rangle\\rangle$ in terms of classical Kauffman brackets of sublinks and the functions $H_k$. The results provide concrete combinatorial tools toward categorifying the tied Jones polynomial and illuminate the structure of AJ-states, with potential extensions to tied Khovanov-type constructions. Overall, the paper advances the understanding of how partitions of components interact with the AJ-bracket and enables practical computations for low-tied cases.
Abstract
The double bracket $\langle \langle \cdot \rangle \rangle$ (also known as the AJ-bracket) is an invariant of framed tied links that extends the Kauffman bracket of classical links. Unlike the classical setting, little is known about the structure of AJ-states (analogous to classical Kauffman states) of a given tied link diagram, and no general state-sum formula for the AJ-bracket is currently available. In this paper we analyze the AJ-states of $2$- and $3$-tied link diagrams, and provide a complete description of their associated resolution trees leading to a computation of $\langle \langle \cdot \rangle \rangle$. As a result, we derive explicit state-sum formulas for the AJ-bracket. These are the first closed-form expressions of this kind, and they constitute a concrete step toward a combinatorial categorification of the tied Jones polynomial.
