Identifying the most influential spreaders is crucial to use limited resource to control spreading in the network. Existing studies of ranking node importance in multilayer networks are mostly based on the network structure, while neglecting how the structural and dynamical couplings of multiple layers impact the spreading influence of nodes in coevolving dynamics. Here we investigate on the identification of influential spreaders in the information-disease coupled spreading dynamics on multiplex networks. Firstly we explicitly reveal that three interlayer coupling factors, which are the two-layer relative spreading rate, the interlayer coupling strength and the interlayer degree correlation, significantly impact the spreading influence of a node in the contact layer where disease spreads. The suppression effect from the information layer makes the structural centrality of nodes in the contact layer fail to predict their influence. Then by mapping the coevolving spreading processes into percolation and using the message-passing approach, we propose a method to calculate the outbreak size of disease starting from a single seed node, which is used to estimate the spreading influence of the node and identify the most influential spreaders in coevolving dynamics on multiplex networks. Our work gives a feasible framework to investigate critical nodes in multiplex networks.
Epidemic spreading processes in the real world can interact with each other in a cooperative, competitive, or asymmetric way, requiring a description based on coevolution dynamics. Rich phenomena such as discontinuous outbreak transitions and hystereses can arise, but a full picture of these behaviors in the parameter space is lacking. We develop a theory for interacting spreading dynamics on complex networks through spectral dimension reduction. In particular, we derive from the microscopic quenched mean-field equations a two-dimensional system in terms of the macroscopic variables, which enables a full phase diagram to be determined analytically. The diagram predicts critical phenomena that were known previously but only numerically, such as the interplay between discontinuous transition and hysteresis as well as the emergence and role of tricritical points.
Brain–computer interfaces have seen extraordinary surges in developments in recent years, and a significant discrepancy now exists between the abundance of available data and the limited headway made in achieving a unified theoretical framework. This discrepancy becomes particularly pronounced when examining the collective neural activity at the micro and meso scale, where a coherent formalization that adequately describes neural interactions is still lacking. Here, we introduce a mathematical framework to analyze systems of natural neurons and interpret the related empirical observations in terms of lattice field theory, an established paradigm from theoretical particle physics and statistical mechanics. Our methods are tailored to interpret data from chronic neural interfaces, especially spike rasters from measurements of single neuron activity, and generalize the maximum entropy model for neural networks so that the time evolution of the system is also taken into account. This is obtained by bridging particle physics and neuroscience, paving the way for particle physics-inspired models of the neocortex.
Graph neural networks (GNNs) excel in modeling relational data such as biological, social, and transportation networks, but the underpinnings of their success are not well understood. Traditional complexity measures from statistical learning theory fail to account for observed phenomena like the double descent or the impact of relational semantics on generalization error. Motivated by experimental observations of “transductive” double descent in key networks and datasets, we use analytical tools from statistical physics and random matrix theory to precisely characterize generalization in simple graph convolution networks on the contextual stochastic block model. Our results illuminate the nuances of learning on homophilic versus heterophilic data and predict double descent whose existence in GNNs has been questioned by recent work. We show how risk is shaped by the interplay between the graph noise, feature noise, and the number of training labels. Our findings apply beyond stylized models, capturing qualitative trends in real-world GNNs and datasets. As a case in point, we use our analytic insights to improve performance of state-of-the-art graph convolution networks on heterophilic datasets.
23 September 2022 in Applied Mathematics and Computation