Locality Spectroscopy of Quantum Statistical Information

This work introduces locality spectroscopy, a coordinate-invariant framework for determining where parameter information first becomes locally identifiable in composite quantum systems. We establish a connection between subsystem information structure and the scaling of Fisher information under controlled local noise, including regular reset and flagged erasure. Reanalysis of public logical-qubit experiments provides complementary tests of higher-body information structure, flagged-erasure Fisher accounting, and correlated-noise effects. The framework offers a reproducible approach to characterizing how quantum information becomes accessible across subsystems.