ZIPPED framework 2.1

This record presents ZIPPED — The Dynamics of Galactic Balance (Version 2.1, Validated), a locked and citable manuscript introducing a geometric, low-acceleration completion of gravitational theory.The ZIPPED framework proposes that galactic stability does not arise from unseen matter components, but from a regime-dependent elastic response of spacetime itself. In high-acceleration environments (the Zipped regime), spacetime behaves rigidly and reproduces General Relativity exactly. Below a critical acceleration threshold �, spacetime undergoes a structural phase transition into an Unraveled regime, in which relaxed elasticity enhances the effective gravitational response across galactic scales.A central result of this work is the identification of a fundamental breakdown of classical scale invariance in the gravitational action. Independent numerical action stress tests conducted by Greg D. Partin (2026) confirm that the ZIPPED action is not invariant under global spatial rescaling, with gradient and potential terms exhibiting distinct scaling behavior. Rather than indicating a defect, this non-scalability is interpreted as a defining physical signature of the spacetime regime transition, formalized here as the Toy Airplane Principle.Within the Unraveled regime, gravity exhibits a fifth-order elastic response, leading to an effective fifth-root radial dependence. This geometric stiffness naturally reproduces flat galactic rotation curves and the baryonic Tully–Fisher relation without invoking Dark Matter particles, exotic fields, or phenomenological interpolation functions. Spectral and algorithmic analyses indicate that the observed “missing mass” corresponds to a geometric phase transition rather than unseen matter.This Zenodo release constitutes a locked theoretical manuscript intended to establish priority, provide a stable citation point, and enable transparent academic discussion. All core concepts, terminology, and structural assumptions are defined within the manuscript. Future extensions may include formalized action derivations, observational tests, and comparative studies, to be released separately.Author: Michel ZwanenburgIndependent numerical validation: Greg D. PartinHashtags#ZIPPED#ModifiedGravity#GalacticDynamics#DarkMatterAlternative#SpacetimeElasticity#ScaleInvariance#Astrophysics#TheoreticalPhysics#GravitationalTheory#Cosmology