We construct explicitly two sequences of triplewise independent random variables having a common but arbitrary marginal distribution $F$ (satisfying very mild conditions) for which a Central Limit Theorem (CLT) does not hold. We obtain, in closed form, the asymptotic distributions of the sample means of those sequences, which are seen to depend on the specific choice of $F$. This allows us to illustrate the extent of the `failure' of the classical CLT under triplewise independence. Our methodology is simple and can also be used to create, for any integer $K$, new $K$-tuplewise independent but dependent sequences (which are useful to assess the ability of independence tests to detect complex dependence). For $K \geq 4$, it appears that the sequences thus created do verify a CLT, and we explain heuristically why this is the case.
翻译:我们明确构建了两个三维独立的随机变量序列,这些变量具有共同但任意的边际分布值$F(满足非常温和的条件),中央限制理论(CLT)对此没有保留。我们以封闭的形式获得了这些序列抽样手段的无症状分布,这似乎取决于具体选择$F。这使我们能够说明经典CLT在三维独立情况下的“失败”程度。我们的方法很简单,也可以用来为任何整数美元创造新的独立但依赖性的单数序列(用于评估独立测试检测复杂依赖性的能力 ) 。 对于 $K\geq 4 美元, 由此创建的序列似乎确实验证了CLT, 我们从理论上解释了为什么情况如此。