English

An operator-theory construction on geometric lattices

Combinatorics 2026-04-13 v2 Operator Algebras

Abstract

We introduce a canonical operator-theoretic construction associated to a finite geometric lattice, in which a simple nonassociative ``diamond product'' on the lattice basis gives rise to a family of creation operators indexed by atoms and a corresponding self-adjoint Hamiltonian on R[L]\mathbb R[L]. A key structural feature is that the Hamiltonian changes rank by at most one, so that its compression to the rank-radial subspace is a Jacobi matrix. In this way, geometric lattices give rise in a direct and uniform manner to finite orthogonal polynomial systems. The Jacobi coefficients admit explicit combinatorial formulas. For Boolean lattices one obtains the centered Krawtchouk Jacobi matrix, while for projective geometries one obtains natural qq-deformations consistent with the qq-Hahn family. The construction applies to arbitrary geometric lattices and requires no symmetry assumptions.

Keywords

Cite

@article{arxiv.2603.24949,
  title  = {An operator-theory construction on geometric lattices},
  author = {Thomas Sinclair},
  journal= {arXiv preprint arXiv:2603.24949},
  year   = {2026}
}

Comments

14 pages, comments welcome! v2: 15 pages, minor revisions for clarity

R2 v1 2026-07-01T11:38:20.127Z