Structural Indifference and the Coherence Operator. Beyond QFT, SR, and GR: Ontology of Physical Realization

This work develops an ontological framework underlying contemporary physical theories, addressing a gap between formal admissibility and physical realization. Modern physics—quantum field theory, special relativity, and general relativity—successfully constrains admissible states, relations, and transitions, yet remains largely silent on how admissible structures become realized physical facts. This paper argues that the limitation is ontological rather than dynamical or epistemic. Two complementary notions are introduced. Structural indifference is the principle according to which physical structure distinguishes roles and invariants, but not the individual identity of the carriers realizing those roles. The coherence operator enforces relational compatibility among admissible roles, ensuring that realized parameter assignments are mutually consistent without fixing absolute numerical values. Together, these notions explain how observable universality can arise without global uniformity of laws or constants. Local variability of parameters becomes compatible with stable structure, while identical observational patterns emerge through coherence and translatability rather than numerical identity. Quantum mechanics is shown to be complete at the level of admissibility but ontologically incomplete with respect to realization. Gravity is interpreted as a global modulator of structural indifference, shaping large-scale regimes of realization without altering quantum formalism. The framework does not modify existing physical theories, introduce new dynamics, or rely on probabilistic selection. Instead, it articulates an ontological layer beneath current formalisms, clarifying why physical description works, how realization occurs, and why identity fixation is unnecessary.