Validation of the Spacetime Flow Hypothesis (SFH): Observational Tests, Theoretical Consistency, and Cosmological Implications

This paper presents a systematic validation of the Spacetime Flow Hypothesis (SFH), a proposed alternative framework to General Relativity and ΛCDM. Where SFH v1 introduced the core postulates, time dilation equations, and cosmological implications of spacetime flow, this follow-up paper focuses on verifying those ideas through empirical testing and mathematical formalism. The results demonstrate that SFH can match or exceed the performance of existing models across key observational domains. The paper includes direct comparisons with observational data—such as galaxy rotation curves, redshift scaling, and quasar time dilation—alongside a full Lagrangian formulation of the theory, complete with field equations derived from the Euler–Lagrange principle. It also introduces a coupling between the flow field and the Higgs field, offering a causal explanation for gravitational time dilation without curvature. The objective is to provide a credible foundation for SFH by resolving open challenges, demonstrating empirical consistency, and elevating the hypothesis to a mathematically testable theory.