Matter-Antimatter Asymmetry from UD Duality: A First-Principles Resolution

We present a first-principles resolution of the matter-antimatter asymmetry from UD theory. The asymmetry is shown to be a necessary consequence of three UD axioms. Antimatter is derived as a phase-flipped configuration of matter, produced only when the critical condition m₀²⟨D_U|D_D⟩ = α⟨D_U|U_D|D_U⟩ is satisfied. This is an instantaneous crossing in the evolving U–D competition. The 1:1 initial symmetry assumed in standard cosmology is absent; antimatter is a derivative of matter. Its extreme rarity follows from the stringency of the critical condition and, in the baryonic sector, from the intrinsic instability of antibaryons. The cosmological evolution is traced from the early universe to the present epoch. The antiproton has a tunneling decay channel absent for the proton, with an order-of-magnitude lifetime estimate of τ_tunn ∼ 300 yr. A comparison with ΛCDM and Standard Model baryogenesis is provided. All conclusions are derived from the UD field equations.