Abstract
This core paper establishes the primitive ontology of the Temporal–Density Framework (TDFT) by treating a single one-dimensional invariant propagation rule as the only fundamental constraint. Volumetric geometry is not assumed but required to emerge as the minimal response needed to preserve this invariant when expressed in isotropic three-dimensional space.
The dimensionless triad α c λ = 1 is shown to encode invariant propagation, gravitational coupling, and linear density as volumetric projections of the same underlying constraint. From this follow the isotropic tension field, radial tension gradients interpreted as gravitational curvature, temporal and lateral projections identified with electric and magnetic components, and the triadic horizon condition relating λ to the Schwarzschild radius. The work provides the axiomatic ground on which Volumes I–III stand, clarifying how their gravitational, electromagnetic, quantum, and cosmological structures arise from preserving a single invariant across volume.