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arXiv 2606.02472math.PRcs.SImath.STstat.TH
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相关均匀附着树

Correlated uniform attachment trees

University of Koblenz(科布伦兹大学);Northwestern University(西北大学);University of Melbourne(墨尔本大学);NJIT(新泽西理工学院)

Johannes Bäumler, Miklós Z. Rácz, Nathan Ross, Anirudh Sridhar

AI总结:

研究一种相关均匀附着树模型,其中两棵树并行生长且附着相关,通过构造基于Jordan中心性和边缘子树大小的统计量,在树规模趋于无穷时一致估计相关参数α。

摘要:

我们引入并研究了一种新的相关均匀附着(UA)树模型,其中相关性贯穿过程的时间演化。在该模型中,两棵UA树并行生长,每一步向每棵树添加一个新节点,并通过边连接到各自树中均匀选择的已有顶点。两次附着选择是相关的:以概率α,两条边连接到两棵树中具有相同时间标签的节点;以概率1-α,选择独立进行。我们研究给定两棵未标记树时该模型的基本检测和估计问题。主要结果中,我们构造了相关参数α的一致估计量,当树规模趋于无穷时成立。该统计量的构造依赖于两个关键思想。首先,我们使用Jordan中心性识别每棵树中顶点子集,其交集具有足够多的共同早期顶点。其次,跨多个时间尺度,可以利用边缘子树的大小近似确定附着到这些早期顶点的顶点标签。我们的分析包括关于保持中心性的早期顶点比例的新定量界,这在网络考古文献中具有独立意义。

英文摘要:

We introduce and study a new model of correlated uniform attachment (UA) trees, where correlation is sprinkled throughout the time evolution of the process. In this model, two UA trees are grown in parallel, and at each time step a new node is added to each tree, with an edge between it and a uniformly chosen existing vertex in the respective tree. The two choices of attachment are correlated: with probability $α$, the edges attach to nodes with the same time label in both trees, and with probability $1-α$, the choices are made independently. We study fundamental detection and estimation questions for this model, given two \emph{unlabeled} trees. In our main result, we construct a consistent estimator of the correlation parameter $α$, as the size of the trees goes to infinity. The construction of our statistic relies on two key ideas. First, we use Jordan centrality to identify subsets of vertices of each tree whose intersection has a sufficient number of common early vertices. The second idea is that, across multiple time scales, it is possible to approximately determine the labels of vertices that have attached to these early vertices, using the sizes of fringe subtrees. Our analysis includes novel quantitative bounds on the fraction of early vertices that remain central, which are of independent interest in the network archaeology literature.

机构、总结、中文摘要均由AI分析而来,可能存在错误,请以论文正文为准。

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