The characterization of an Alternating Sign Matrix using a triplet
Toyokazu Ohmoto
TL;DR
The paper establishes a cohesive framework to characterize Alternating Sign Matrices (ASMs) by linking them to the six-vertex model and to height functions through a per-entry triplet $({a}_{i,j},{c}_{i,j},{r}_{i,j})$. It then derives a bijection between ASM data and height functions via the explicit formula ${h}_{i,j}=i+j-2\sum_{1\le k\le i,1\le l\le j}{a}_{k,l}$ with an explicit inverse, enabling a transfer of combinatorial structure between ASMs, SV configurations, and height-function matrices. The work further integrates the Fully Packed Loop (FPL) perspective, defining link patterns and operators on them, and develops Wieland gyration and dihedral-symmetry theory to study symmetry-induced refinements of counts. Finally, it constructs a vector-space framework on link patterns, introduces projection and Hamiltonian-like operators, and outlines future research directions including half-turn ASMs and potential connections to root systems. Overall, the paper provides a concrete, triplet-based blueprint to translate ASM enumeration problems into combinatorial and algebraic settings linked to SV, FPL, and height-function formalisms, with symmetry principles guiding structure and potential extensions.
Abstract
Alternating Sign Matrix(ASM for short) is a square matrix which is consist of 0, 1 and -1. In this paper, we characterize an ASM by showing a bijection between alternating sign matrix and six vertex model, and a bijection between six vertex model and height function. In order to show these bijections, we define a triplet $({a}_{i, j}, {c}_{i, j}, {r}_{i, j})$ for each entry of an ASM. We also define a \textsl{track} for each index of height function, and state more properties of height function.
