21,035 research outputs found

    Testing goodness-of-fit of random graph models

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    Random graphs are matrices with independent 0, 1 elements with probabilities determined by a small number of parameters. One of the oldest model is the Rasch model where the odds are ratios of positive numbers scaling the rows and columns. Later Persi Diaconis with his coworkers rediscovered the model for symmetric matrices and called the model beta. Here we give goodnes-of-fit tests for the model and extend the model to a version of the block model introduced by Holland, Laskey, and Leinhard

    Synchronization in random networks with given expected degree sequences

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    Synchronization in random networks with given expected degree sequences is studied. We also investigate in details the synchronization in networks whose topology is described by classical random graphs, power-law random graphs and hybrid graphs when N goes to infinity. In particular, we show that random graphs almost surely synchronize. We also show that adding small number of global edges to a local graph makes the corresponding hybrid graph to synchroniz

    Moment-Based Spectral Analysis of Random Graphs with Given Expected Degrees

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    In this paper, we analyze the limiting spectral distribution of the adjacency matrix of a random graph ensemble, proposed by Chung and Lu, in which a given expected degree sequence w‾nT=(w1(n),…,wn(n))\overline{w}_n^{^{T}} = (w^{(n)}_1,\ldots,w^{(n)}_n) is prescribed on the ensemble. Let ai,j=1\mathbf{a}_{i,j} =1 if there is an edge between the nodes {i,j}\{i,j\} and zero otherwise, and consider the normalized random adjacency matrix of the graph ensemble: An\mathbf{A}_n == [ai,j/n]i,j=1n [\mathbf{a}_{i,j}/\sqrt{n}]_{i,j=1}^{n}. The empirical spectral distribution of An\mathbf{A}_n denoted by Fn(⋅)\mathbf{F}_n(\mathord{\cdot}) is the empirical measure putting a mass 1/n1/n at each of the nn real eigenvalues of the symmetric matrix An\mathbf{A}_n. Under some technical conditions on the expected degree sequence, we show that with probability one, Fn(⋅)\mathbf{F}_n(\mathord{\cdot}) converges weakly to a deterministic distribution F(⋅)F(\mathord{\cdot}). Furthermore, we fully characterize this distribution by providing explicit expressions for the moments of F(⋅)F(\mathord{\cdot}). We apply our results to well-known degree distributions, such as power-law and exponential. The asymptotic expressions of the spectral moments in each case provide significant insights about the bulk behavior of the eigenvalue spectrum
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