A time-direction field linking gravitational redshift, decoherence and horizon thermality

Abstract We propose an internal two-component time-direction field T = (Tr, Ti) whose orientation ϑ(x) simultaneously rescales gravitational lapse factors and weights coherent versus dissipative dynamics. The framework yields six testable signatures: (i) a multiplicative renormalization of gravitational redshift; (ii) a strictly positive, platform-independent decoherence floor; (iii) a rescaling of black-hole and analogue-horizon temperatures consistent with Euclidean regularity; (iv) linear-response "tomography" linking fractional frequency drift and dephasing; (v) cosmological background dynamics with wϑ∈-1,+1; and (vi) correlated temporal-noise spectra across heterogeneous sensors. We derive parameter-independent bounds, show compatibility with causality and thermodynamics, and outline null tests spanning optical clocks, superconducting qubits, atom interferometers and horizon analogues. Using current performance levels, we map the allowed orientation today. Phenomena usually treated separately (Wick rotation, tunnelling, Unruh/Hawking thermality) emerge as geometric tilts of T. The programme is falsifiable: a single angle ϑ controls all departures from established theory, enabling decisive cross-platform tests with near-term experiments.