Spatiotemporal Signature Vectors and Entanglement Networks: From Scalar Bell Tests to Event-Level Quantum Diagnostics

This work introduces the concept of spatiotemporal signatures (Σ) as a diagnostic layer for analyzing quantum entanglement. By retaining and quantifying temporal and spatial correlations from raw CHSH-type coincidence datasets, Σ captures structure beyond conventional Bell statistics. Using Σ-distance graphs, we demonstrate how Bell-identical experiments can separate into distinct clusters, revealing entanglement networks whose membership is defined by shared correlation properties rather than time or space. The framework enables network-level metrics such as coherence, diameter, and membership entropy, and naturally connects to quantum repeaters, satellite-based entanglement distribution, and emerging quantum internet architectures. This approach is designed to augment traditional entanglement certification without altering its theoretical foundations, providing a scalable and operational method for characterizing multipartite and distributed quantum correlations.