The $\boldsymbol{\beta}$-model for random graphs is commonly used for representing pairwise interactions in a network with degree heterogeneity. Going beyond pairwise interactions, Stasi et al. (2014) introduced the hypergraph $\boldsymbol{\beta}$-model for capturing degree heterogeneity in networks with higher-order (multi-way) interactions. In this paper we initiate the rigorous study of the hypergraph $\boldsymbol{\beta}$-model with multiple layers, which allows for hyperedges of different sizes across the layers. To begin with, we derive the rates of convergence of the maximum likelihood (ML) estimate and establish their minimax rate optimality. We also derive the limiting distribution of the ML estimate and construct asymptotically valid confidence intervals for the model parameters. Next, we consider the goodness-of-fit problem in the hypergraph $\boldsymbol{\beta}$-model. Specifically, we establish the asymptotic normality of the likelihood ratio (LR) test under the null hypothesis, derive its detection threshold, and also its limiting power at the threshold. Interestingly, the detection threshold of the LR test turns out to be minimax optimal, that is, all tests are asymptotically powerless below this threshold. The theoretical results are further validated in numerical experiments. In addition to developing the theoretical framework for estimation and inference for hypergraph $\boldsymbol{\beta}$-models, the above results fill a number of gaps in the graph $\boldsymbol{\beta}$-model literature, such as the minimax optimality of the ML estimates and the non-null properties of the LR test, which, to the best of our knowledge, have not been studied before.
翻译:随机图的$\boldsymbol{\beta}$模型常用于表示具有度异质性的网络中的成对交互。超越成对交互,Stasi等人(2014)引入了超图$\boldsymbol{\beta}$模型,用于捕捉具有高阶(多路)交互的网络中的度异质性。本文启动了多层超图$\boldsymbol{\beta}$模型的严格研究,该模型允许跨层的不同大小超边。首先,我们推导了极大似然估计的收敛速度并建立了其极小极大速率最优性。我们还推导了极大似然估计的极限分布,并构建了模型参数的渐近有效置信区间。其次,我们考虑了超图$\boldsymbol{\beta}$模型中的拟合优度问题。具体地,我们在原假设下建立了似然比检验的渐近正态性,推导了其检测阈值以及阈值处的极限功效。有趣的是,似然比检验的检测阈值被证明是极小极大最优的,即所有检验在此阈值以下渐近无效。这些理论结果在数值实验中得到了进一步验证。除了为超图$\boldsymbol{\beta}$模型建立估计和推断的理论框架外,上述结果填补了图$\boldsymbol{\beta}$模型文献中的若干空白,例如极大似然估计的极小极大最优性和似然比检验的非零性质——据我们所知,这些此前尚未被研究过。