Probabilistic Entry Swapping Bijections for Non-Attacking Fillings
Guilherme Zeus Dantas e Moura, Olya Mandelshtam
TL;DR
This work addresses symmetry properties of permuted-basement Macdonald polynomials by developing a fully combinatorial, probabilistic bijection on non-attacking fillings. It generalizes Mandelshtam's partition-focused bijection to composition shapes, enabling a weight-preserving swap of adjacent basement entries that underpins the symmetry E_α^σ(x;q,t) = E_α^{σ s_i}(x;q,t). The authors prove this symmetry for α_i = α_{i+1} without requiring σ_i and σ_{i+1} to be consecutive, thereby extending prior results from Ale19 and CHMMW22. The approach relaxes earlier hypotheses and provides a unified combinatorial framework for composition-shaped non-attacking fillings with potential broader implications in Macdonald polynomial theory.
Abstract
Non-attacking fillings are combinatorial objects central to the theory of Macdonald polynomials. A probabilistic bijection for partition-shaped non-attacking fillings was introduced by Mandelshtam (2024) to prove a compact formula for symmetric Macdonald polynomials. In this work, we generalize this probabilistic bijection to composition-shaped non-attacking fillings. As an application, we provide a bijective proof to extend a symmetry theorem for permuted-basement Macdonald polynomials established by Alexandersson (2019), proving a version with fewer assumptions.
