Source-First Exhaustion of the Physical Carrier Universe

Neutrino carrier ARC and HNL prediction 3/18 This paper develops a source-first candidate-completeness theorem for the physical carrier architectures capable of realizing the neutrino propagation role complex established in the preceding PCR papers. Earlier work identifies the target-specific physical roles required by the realized neutrino source–propagation–detection interface and constructs the corresponding carrier-neutral interface. The present paper addresses the next logically prior question: what physical carrier architectures are available to perform those roles, before any downstream adequacy, survival, ranking, or model-selection result is used? A semantic class of same-target physical carrier realizations is defined from an independently specified physical ontology. Each realization is reduced to its currently participating carrier core, separating actual target-relative carrier work from merely latent capability. A carrier-facing trace records support, persistence mode, derivation status, constituent kind, intrinsic typed data, parameter domains, target attachment, and the complete physical incidence architecture. Source activity is evaluated pointwise over parameter space. Source-null incidences and disconnected latent sectors are removed before carrier-path closure, while every source-active incidence is retained without imposing an arbitrary numerical coupling threshold. The resulting trace is proved to be a complete invariant of carrier-semantic equivalence. From the fixed target and physical ontology, the paper independently generates a source carrier theory containing the relevant source sorts, lawful operations, constitutive equations, and typed activity/null structure. Local typing is kept distinct from source-constitutive coherence, and both are separated from later physical admissibility and interface adequacy. The resulting candidate universe includes normal-form regions for: existing-substrate and law-only structures; new local carriers; composite and emergent sectors; topological and defect-supported sectors; solitonic and boundary structures; environmental co-carriers; hidden or enlarged-state-space sectors; and finite hybrid architectures. These strata are generated from the source theory rather than selected from a pre-existing list of preferred mechanisms. Symbolic representation labels, multiplicities, couplings, global data, and other source parameters remain open. The principal theorem establishes a canonical isomorphism between the semantic class of finitely presented same-target carrier realizations modulo carrier-semantic equivalence and the generated source-first candidate universe. Thus every candidate in the declared comparison class admits a source-generated normal form, and every generated instance has a coherent physical carrier interpretation. A separate independence theorem shows that candidate formation depends only on the fixed source data. Downstream interface values, simultaneous-survival results, rankings, and expected-occupant labels cannot alter the candidate universe or be used to backfit its contents. The result is deliberately bounded. Membership in the generated universe does not imply interface adequacy, anomaly or vacuum compatibility, simultaneous survival, role eligibility, physical realization, or experimental preference. The theorem supplies the complete target-relative candidate domain on which those later questions can be posed.