The Coherence Signature - Five Criteria for Identifying Systems in Resonance with the Quantum Vacuum

This paper describes the Coherence Signature — a set of five structural criteria that appear together wherever physical systems maintain stable coherence with the quantum vacuum or exhibit anomalous energy phenomena. The five criteria are: (C1) Topological Closure, (C2) Scalar Self-Consistency, (C3) Phase Criticality, (C4) Coherent Medium, and (C5) Temporal Coherence. The Coherence Signature is formulated material-agnostically and scale-invariantly — as a recognition tool applicable across all scientific disciplines. Its derivation is inductive, drawing from experimentally supported observations in biophysics, quantum physics, field theory, and materials science. The paper concludes with an overview of known systems that fully or partially exhibit the Coherence Signature, and an outlook on possible applications in the design of technical resonators.