On the Symmetric Structure of Relativistic Matter and Its Gravitational Response

We propose an algebraic framework to reinterpret the source term linking relativistic matter and gravity. By enforcing a decomposition of the Dirac field based on Charge-Conjugation (C) symmetry, we establish the “bi-particle” - an irreducible symmetric excitation effective above the Compton scale - as the fundamental ontological unit of gravitation. The Energy-Momentum Tensor is shown to separate rigorously into C-even diagonal terms (mass source) and C-odd cross terms (charge source). In macroscopic neutral matter, C-symmetry necessitates the vanishing of these cross-terms, leaving the positive-definite symmetric sector as the sole gravitational contributor. This perspective resolves the standing conceptual tension between QFT localization limits and the Weak Equivalence Principle, providing a microphysical basis for the universality of free fall, while simultaneously recovering Maxwellian electrodynamics from the C-odd mixing sector.