English

Colored interlacing triangles and Genocchi medians

Combinatorics 2026-02-05 v1 Quantum Algebra

Abstract

Colored interlacing triangles, introduced by Aggarwal-Borodin-Wheeler (2024), provide the combinatorial framework for the Central Limit Theorem for probability measures arising from the Lascoux-Leclerc-Thibon (LLT) polynomials. Colored interlacing triangles depend on two key parameters: the number of colors nn and the depth of the triangle NN. Recent work of Gaetz-Gao (2025) connects these objects to Schubert calculus and resolves the enumeration for n=3n=3 and arbitrary depth NN. However, the enumerative behavior for general nn has remained open. In this paper, we analyze the complementary regime: fixed depth N=2N=2 and arbitrary number of colors nn. We prove that in this setting, colored interlacing triangles are in bijection with Dumont derangements, identifying their enumeration with the Genocchi medians. This connects the probabilistic model to a rich hierarchy of classical combinatorial objects. Furthermore, we introduce a qq-deformation of this enumeration arising naturally from the LLT transition energy. This yields new qq-analogs of the Genocchi medians. Finally, we present computational results and sampling algorithms for colored interlacing triangles with higher NN or nn, which suggests the limits of combinatorial tractability in the (N,n)(N,n) parameter space.

Keywords

Cite

@article{arxiv.2602.04390,
  title  = {Colored interlacing triangles and Genocchi medians},
  author = {Natasha Blitvic and Leonid Petrov},
  journal= {arXiv preprint arXiv:2602.04390},
  year   = {2026}
}

Comments

21 pages, 4 figures. Code on GitHub linked in text

R2 v1 2026-07-01T09:35:40.453Z