Operational Holonomy: A Null Test for Non-Metric Signal Degradation in Vacuum

This paper introduces operational holonomy as a null test for detecting non-metric signal degradation in vacuum. By comparing closed causal loops under controlled signal propagation, the method isolates cumulative signal distortion effects independent of curvature or coordinate choice. The framework provides a falsifiable experimental pathway for testing causal degradation mechanisms beyond standard geometric interpretations of spacetime. Keywords Causality; Strain; Finite Signal Speed; Holonomy; Signal Degradation; Vacuum Physics