Shuffle theorem for torus link homology
Donghyun Kim, Jaeseong Oh
TL;DR
This work establishes a torus-link analogue of the shuffle theorem by proving that the elliptic Hall algebra action $e_{(1^k)}[-MX^{m,n}]\cdot 1$ generates the combinatorial data of $k$-tuples of cyclic $(m,n)$-parking functions, thereby linking symmetric-function operators to Khovanov–Rozansky homology of torus links $T(km,kn)$. The authors develop a determinantal, Jacobi–Trudi style framework using new $\mathfrak{h}$-operators and a rational Shareshian–Wachs involution via wiggle diagrams, reformulating the rational shuffle theorem in terms of $P$-tableaux and a statistic-preserving bijection to standard parking-function tuples. This approach yields a direct combinatorial expression for $e_{(1^k)}[-MX^{m,n}]\cdot 1$ as a generating function over cyclic parking functions and provides elementary proofs of Loehr–Warrington type formulas for $\nabla^m s_{\lambda}$, thereby enriching the interplay between elliptic Hall algebras, diagonal coinvariants, and knot homology. The results give a rigorous spine for the knot-theoretic conjectures of GMV17 and Wilson in the torus-link case and illuminate how new determinantal operator methods can drive positive Laurant expansions in this highly structured setting.
Abstract
We prove that the symmetric function $e_{(1^k)}[-MX^{m,n}] \cdot 1$, arising from the elliptic Hall algebra, equals the generating function for $k$-tuples of cyclic $(m,n)$-parking functions. This result resolves a conjecture of Gorsky--Mazin--Vazirani and Wilson, establishing that the elliptic Hall algebra governs the Khovanov--Rozansky homology of torus links $T(km,kn)$. Consequently, this provides an affirmative answer to a question of Galashin and Lam in the torus link case. As a key step in the proof, we develop a rational analogue of the Shareshian--Wachs involution originally introduced to prove the symmetry property of the chromatic quasisymmetric functions.
