Matter–Antimatter Asymmetry as the Unique Admissible Reconstruction of Persistent Cosmological Identity

Overview This paper develops an AASC account of matter–antimatter asymmetry as a structural reconstruction theorem rather than a new baryogenesis mechanism. It does not alter Standard Model dynamics, derive the baryon-to-photon ratio, compute CP-sector numerical values, or select a specific physical mechanism such as leptogenesis or electroweak baryogenesis. The central question is prior to mechanism-building: under what conditions can a cosmological history support persistent material reference after irreversible loss of the correlations needed to transport exact matter–antimatter exchangeability? Central Result The paper proves that, on a fixed cosmological material-reference scope, exact matter–antimatter exchangeability cannot serve as a late same-history identity symmetry on the burden-realizing support once genuine retrieval-irreversibility has removed the exchangeability preservation certificate. The resulting structural object is a boundary-fixed admissible surplus reconstruction class, carried by persistent anchor witnesses in the post-irreversible anchor quotient. Main Contributions Defines the fixed reconstruction category for persistent material-reference histories. Separates global exchange-totalization failure, burden-restricted obstruction, and burden-wide lower-bound support. Shows that burden-restricted exchange obstruction gives nonempty burden-relevant witness support. Shows that, under burden-wide exchange non-transportability, the witness rank is bounded below by the declared material-reference burden (\rho_S). Establishes sign fixation on sign-coherent material-standing scopes. Distinguishes the structural surplus reconstruction class from numerical baryon abundance. Reinterprets baryogenesis mechanisms as downstream physical realizations of a prior admissibility constraint. Relation to Standard Baryogenesis The paper is compatible with standard baryogenesis programs. Freeze-out, electroweak baryogenesis, leptogenesis, sphaleron conversion, inflationary dilution, reheating, and entropy-producing dispersal may generate, transfer, protect, dilute, or convert projected particle-number asymmetry inside declared physical models. Their AASC status is that they occupy or witness the already-forced admissible surplus reconstruction class. They do not generate the admissibility of that class by later redescription. Scope and Nonclaims The paper does not claim to derive: the baryon-to-photon ratio; the observed numerical baryon abundance; CP phase values; CKM or PMNS coordinates; a specific baryogenesis model; a privileged quark sector; a violation of microscopic CPT symmetry. Its result is a fixed-domain structural theorem concerning exchangeability non-transportability, persistent material-reference reconstruction, and boundary-fixed surplus-class admissibility. Keywords AASC; matter–antimatter asymmetry; baryogenesis; admissibility; standing; persistent material reference; exchangeability non-transportability; retrieval-irreversibility; anchor quotient; surplus reconstruction class; boundary-fixed reconstruction; sign fixation; cosmological identity; Sakharov conditions; leptogenesis; electroweak baryogenesis; CP violation; CPT symmetry; structural cosmology; philosophy of cosmology; foundations of physics; constraint formalism This paper is downstream of: Non-Degenerate Construction and the Kernel of Admissibility  The Structure of Admissibility