论文标题
无与伦比的随机图具有无限均值的健身变量
Inhomogeneous random graphs with infinite-mean fitness variables
论文作者
论文摘要
我们考虑一个不均匀的erdős-rényi随机图集合,其指数衰减的随机断开概率由I.I.D.确定。与图形顶点相关的具有重尾巴和无限平均值的变量场。最近在Garuccio等人的物理文献中研究了该模型。 (2020)在网络重新归一化的上下文中,作为标尺不变的随机图。从数学角度来看,该模型符合无尺度的不均匀随机图的类别,其渐近几何特征最近引起了人们的兴趣。对于这种类型的图,当基础顶点变量具有有限的均值和方差时,已经知道几个结果,但在这里,我们考虑了具有无限均值的单方面稳定变量的情况。为了简化我们的分析,我们假设变量是从带有参数$α\ in(0,1)$的帕累托分布中采样的。我们首先表征典型程度和一些相关可观察到的渐近分布。特别是,我们表明,在适当缩放后,顶点的分布程度与混合泊松定律相聚。然后,我们表明,不同顶点程度之间的相关性在渐进式上是渐进的,但同时,当关节拉普拉斯的行为转换围绕零时,发现了一种渐近尾独立性的形式。此外,我们提出了一些有关楔形和三角形的渐近密度的发现,并为灰尘(即断开的顶点)展示了跨界。
We consider an inhomogeneous Erdős-Rényi random graph ensemble with exponentially decaying random disconnection probabilities determined by an i.i.d. field of variables with heavy tails and infinite mean associated to the vertices of the graph. This model was recently investigated in the physics literature in Garuccio et al. (2020) as a scale-invariant random graph within the context of network renormalization. From a mathematical perspective, the model fits in the class of scale-free inhomogeneous random graphs whose asymptotic geometrical features have been recently attracting interest. While for this type of graphs several results are known when the underlying vertex variables have finite mean and variance, here instead we consider the case of one-sided stable variables with necessarily infinite mean. To simplify our analysis, we assume that the variables are sampled from a Pareto distribution with parameter $α\in(0,1)$. We start by characterizing the asymptotic distributions of the typical degrees and some related observables. In particular, we show that the degree of a vertex converges in distribution, after proper scaling, to a mixed Poisson law. We then show that correlations among degrees of different vertices are asymptotically non-vanishing, but at the same time a form of asymptotic tail independence is found when looking at the behavior of the joint Laplace transform around zero. Moreover, we present some findings concerning the asymptotic density of wedges and triangles and show a cross-over for the existence of dust (i.e. disconnected vertices).