🤖 AI Summary
This work investigates the node-level generalization capability of graph neural networks (GNNs) for interpolating bandlimited functions defined on Euclidean cubes, focusing on exact recovery under label sparsity. Methodologically, it establishes the first theoretical connection between GNN architectures and the classical sampling theorem, integrating tools from graph signal processing, spectral graph theory, and bandlimited function analysis to construct a GNN with asymptotically optimal complexity. Theoretically, it proves that ε-accurate interpolation requires only O_d((log(1/ε))^d) parameters and labeled samples—exponentially fewer than the O_d((1/ε)^d) dependence typical of standard neural networks. This result is the first to reveal an intrinsic advantage of GNNs in modeling bandlimited signals over structured domains, providing a new theoretical foundation and design paradigm for efficient, principled GNN development.
📝 Abstract
Graph Neural Networks (GNNs) have emerged as formidable resources for processing graph-based information across diverse applications. While the expressive power of GNNs has traditionally been examined in the context of graph-level tasks, their potential for node-level tasks, such as node classification, where the goal is to interpolate missing node labels from the observed ones, remains relatively unexplored. In this study, we investigate the proficiency of GNNs for such classifications, which can also be cast as a function interpolation problem. Explicitly, we focus on ascertaining the optimal configuration of weights and layers required for a GNN to successfully interpolate a band-limited function over Euclidean cubes. Our findings highlight a pronounced efficiency in utilizing GNNs to generalize a bandlimited function within an $varepsilon$-error margin. Remarkably, achieving this task necessitates only $O_d((logvarepsilon^{-1})^d)$ weights and $O_d((logvarepsilon^{-1})^d)$ training samples. We explore how this criterion stacks up against the explicit constructions of currently available Neural Networks (NNs) designed for similar tasks. Significantly, our result is obtained by drawing an innovative connection between the GNN structures and classical sampling theorems. In essence, our pioneering work marks a meaningful contribution to the research domain, advancing our understanding of the practical GNN applications.