STGS: Spatio-temporal Graph Sparsification Using Reinforcement Learning

Spatio-temporal graphs encode dynamic interactions across space and time, but their size and complexity pose challenges for analysis and computation. Graph sparsification provides an effective solution to these issues by reducing the number of edges while preserving the essential structural and dynamic properties of the network. This reduction is crucial for enhancing the interpretability of complex graphs, revealing hidden patterns, and enabling more efficient computational analysis. However, real-world graphs often exhibit continuous spatial and temporal evolution, which most existing sparsification algorithms, primarily designed for static graphs, fail to address. We introduce STGS (Spatio-Temporal Graph Sparsification), a reinforcement learning-based framework for sparsifying spatio-temporal graphs. By learning to prune edges while preserving key spatio-temporal patterns, STGS enables efficient analysis of evolving systems. Experiments on real-world datasets demonstrate that STGS outperforms existing methods in both structural preservation and downstream forecasting tasks.