“多米诺”是一种特殊实体,由硬二聚体状核心和软外壳组成,并受局部相互作用支配。“软外壳”和“硬核心”意味着外壳可以重叠,而核心在排斥势下作用。与统计物理中的二聚体问题(该问题列出给定 n x n 晶格的所有可能配置数量)不同,本文更适度的目标是为菱形中允许的最大多米诺数量提供上下界。在这个 NP 问题中,提出了一种确定性构造规则,并导致一个次优解 ψ_n 作为下界。随后注入某种无序性,并导致一个上界 ψ_n_upper,该上界是否可达取决于情况。在某些情况下,下界和上界重合,因此 ψ_n = ψ_n_upper 成为最大配置的多米诺确切数量。
英文摘要:
"Dominos" are special entities consisting of a hard dimer-like kernel surrounded by a soft hull and governed by local interactions. "Soft hull" and "hard kernel" mean that the hulls can overlap while the kernel acts under a repulsive potential. Unlike the dimer problem in statistical physics, which lists the number of all possible configurations for a given n x n lattice, the more modest goal herein is to provide lower and upper bounds for the maximum allowed number of dominos in the diamond. In this NP problem, a deterministic construction rule is proposed and leads to a suboptimal solution ψ_n as a lower bound. A certain disorder is then injected and leads to an upper bound ψ_n_upper reachable or not. In some cases, the lower and upper bounds coincide, so ψ_n = ψ_n_upper becomes the exact number of dominos for a maximum configuration.
In this article we define a generalization of the domino shuffling algorithm for tilings of the Aztec diamond to the interacting $k$-tilings recently introduced by S. Corteel, A. Gitlin, and the first author. We describe the algorithm both in terms of dynamics on a system of colored particles and as operations on the dominos themselves.
A recent conjecture of Di Francesco states that the number of domino tilings of a certain family of regions on the square lattice is given by a product formula reminiscent of the one giving the number of alternating sign matrices. These regions, denoted ${\mathcal T}_n$, are obtained by starting with a square of side-length $2n$, cutting it in two along a diagonal by a zigzag path with step length two, and gluing to one of the resulting regions half of an Aztec diamond of order $n-1$. Inspired by the regions ${\mathcal T}_n$, we construct a family $C_{m,n}^{a,b,c,d}$ of cruciform regions gener…