Strong-Field Validation of the Spacetime Flow Hypothesis: Gravitational Wave Orbital Decay from First Principles

This standalone paper presents a strong-field test of the Spacetime Flow Hypothesis (SFH) using the orbital decay of relativistic binary pulsars. SFH is a Lorentz-invariant, curvature-free field theory in which gravity and gravitational radiation arise from resistance to a physical flow of proper time, rather than from spacetime curvature. The analysis derives the leading-order radiative energy-loss scaling predicted by SFH for compact binaries and shows that it reproduces the same functional dependence on component masses and orbital separation as the standard quadrupole formula. Gravitational radiation is modeled as causal, transverse disturbances of the time-flow field that propagate at the speed of light and carry energy away from the system. Calibration is performed using a single well-measured reference system (the double pulsar PSR J0737–3039). The calibrated normalization is then held fixed and applied to a restricted set of relativistic binaries with well-constrained intrinsic orbital-decay measurements, which are treated as genuine out-of-sample consistency checks. Comparisons are carried out directly in the timing observable PBDOT, the quantity measured by pulsar timing experiments. Across the retained systems, SFH reproduces the observed decay magnitudes, signs, and parametric scaling within reported observational uncertainties, without system-dependent tuning. The analysis is limited to leading-order secular energy loss and does not claim detailed waveform or high-order post-Newtonian equivalence. This paper is part of a broader set of SFH validation studies spanning gravitational waves, supernovae, galaxy dynamics, and lensing — together offering a consistent, testable alternative to GR and ΛCDM grounded in the physical flow of time. Foundational Theory Spacetime Flow Hypothesis — Core Field-Theoretic Framework. DOI : https://doi.org/10.5281/zenodo.18140096 Defines the flow-field, scalar resistance α(x), drift law, energy conservation, and Lagrangian. Empirical Validation SN1a — Luminosity distance + time dilation (χ²/dof = 0.934). DOI: https://doi.org/10.5281/zenodo.18217479 Galaxy Rotation Curves — 20/20 fits without dark matter. DOI: https://doi.org/10.5281/zenodo.18136466 Gravitational Lensing Time Delays — 10 strong-lens delays from baryons only. DOI : https://doi.org/10.5281/zenodo.18136510 Predictive Frontier (New V2) Fast-Flow Bubble — Local void explains Hubble tension (11σ match to Pantheon+ residuals). DOI : https://doi.org/10.5281/zenodo.18136251 (New V2) ISW Effect — The Integrated Sachs–Wolfe Effect without Dark Energy: A Causal Gradient Prediction. DOI : https://doi.org/10.5281/zenodo.18136185 (New) Filament Rotation — Cosmic filaments rotate only when ∇α is asymmetric. DOI : https://doi.org/10.5281/zenodo.18141156 Together with prior empirical validations of SFH across binary pulsars, supernova time dilation, galaxy rotation curves, gravitational lensing delays, and large-scale ISW correlations, filament-rotation result supports a unified, causal interpretation of gravity based on gradients in the flow of proper time. Version 4 (January 2026) Clarifies unit conventions, standardizes the treatment of timing observables, and restricts the system sample to binaries with robust intrinsic decay measurements. No equations, calibration procedures, numerical methods, or scientific conclusions have been changed. Correspondence: Daniel Beaupré — GitHub: https://github.com/dbeaup01