The Ultimate Relativity: A Self-Consistent Unification of Spacetime Ontology, Tachyonic Shadow Dynamics, Charge-Energy Equivalence, and Gravity from Four Postulates with Zero Free Parameters

We present the complete, self-consistent framework of the Ultimate Relativity (UR): four ontological postulates that simultaneously provide a deeper foundation for quantum mechanics, general relativity, and electromagnetism. The Space Postulate identifies every physical entity as a localised restructuring of space itself; the Pair Postulate asserts that every particle is co-created with a superluminal shadow of opposite quantum numbers; the Time Postulate grounds particle existence in discrete de Broglie clock ticks; and the Measurement Postulate identifies detection with a particle–shadow coincidence event. From these four postulates alone we derive: 1. the tachyonic Dirac equation as the unique shadow wave equation, together with the Quantex identity-exchange mechanism that bounds tachyon condensation to a maximum growth of e¹ ≈ 2.718 independent of momentum; 2. the charge-energy equivalence qm = γq₀ and the Proton–Electron Charge Asymmetry Principle—the proton rest charge is a Lorentz-invariant Chern–Simons winding number while the electron rest charge satisfies q₀(e) = e₀/γ, with all QED observables exactly reproduced via the γ-cancellation theorem; 3. the UR-Dirac equation, in which charge is an energy-dependent operator; 4. the corrected Born rule derived from the tachyonic propagator (correcting an error in the original paper), with a falsifiable deviation δ(Q²) = exp(−2πmₛc²/√Q²) testable at the Electron-Ion Collider; 5. the photocity scalar field ρ = dE/dV, its unique action (fixed by four constraints, zero free parameters beyond the cosmological constant), and the effective mass formula mᵉᵠᵠ = m₀(1−ρ/ρ₀) from a Yukawa self-consistency condition; and 6. the Einstein equations, Newtonian gravity, and dark energy, all recovered without new fields. Three hadronic observables are computed with zero free parameters: the neutron magnetic moment −1.913 μN (four significant figures), the proton dipole form factor shape, and the sign of the neutron mean-square charge radius. The framework is internally consistent, compatible with all precision measurements, and makes concrete falsifiable predictions testable by 2030.