We introduce a partial decidability protocol for the Wang tiling problem (which is the prototype of undecidable problems in combinatorics and statistical physics) by constructing a suitable mapping from tilings of finite squares of different sizes. Such mapping depends on the initial family of Wang tiles (the alphabet) with which one would like to tile the plane. This allows to define effective entropy and temperature associated to the alphabet (together with the corresponding partition function). We identify a subclass of good alphabets by observing that when the entropy and temperature of a given alphabet are well-behaved in the thermodynamical sense then such alphabet is a good candidate to tile the infinite two-dimensional plane. Our proposal is tested successfully with the known available good alphabets (which produce periodic tilings, aperiodic but self-similar tilings as well as tilings which are neither periodic nor self-similar). Our analysis shows that the Kendall Tau coefficient is able to distinguish alphabets with a good thermodynamical behavior from alphabets with bad thermodynamical behavior. The transition from good to bad behavior is related to a transition from non-chaotic to chaotic regime in discrete dynamical systems of logistic type.
翻译:本文针对Wang铺砖问题(组合数学与统计物理中不可判定问题的原型),通过构造有限大小正方形铺砖的适当映射,提出了一种部分可判定性协议。该映射依赖于初始的Wang砖块族(字母表),人们希望用该字母表铺满平面。由此可以定义与字母表相关的有效熵和温度(以及相应的配分函数)。通过观察发现,当给定字母表的熵和温度在热力学意义上表现良好时,该字母表是铺满无限二维平面的良好候选者,从而识别出一类“良好字母表”子类。我们的方案在已知的可用良好字母表上成功进行了测试(这些字母表可产生周期性铺砖、非周期性但自相似铺砖,以及既非周期性也非自相似的铺砖)。分析表明,Kendall Tau系数能够区分具有良好热力学行为的字母表与不良热力学行为的字母表。从良好行为到不良行为的转变,与逻辑型离散动力系统中从非混沌态到混沌态的转变相关。
Alphabet is mostly a collection of companies. This newer Google is a bit slimmed down, with the companies that are pretty far afield of our main internet products contained in Alphabet instead.https://abc.xyz/