Inverted Hypersphere Cosmology: Subatomic Structure from RP4 Topology

We extend the Inverted Hypersphere Cosmology (IHC) series into the subatomic sector, deriving five results with zero free parameters beyond the IHC mass axiom m (k) = mₑ × phiᵏ. First, the proton-to-electron mass ratio is derived as mₚ/mₑ = Z2² × Z3³ × kₜau = 4 × 27 × 17 = 1836, matching the observed value to 0. 008%. All three factors are independently derived from RP4 topology: Z2² = 4 from the spatial and colour-phase antipodal boundary conditions, where the colour-phase factor follows from the chain reflection j → 23−j swapping colour classes R and B and sending epsilon^RGB → −epsilon^RGB; Z3³ = 27 from SO (8) triality; and kₜau = 17 as the unique odd Class-B shell in the lepton spectral bracket kₘu, k₄th = 11, 23, confirmed as the fixed point of the spectral involution k → 34−k. The leading-order QED correction Delta = 8*alpha*phi² = 0. 15284 mₑ is derived from the 8 Class-G self-dual modes of the 22-site co-rotating chain (0. 11% from observed). Second, the strong-CP problem is resolved topologically: on RP4 = S4/Z2 the antipodal map reverses orientation, forcing the Pontryagin index Q = integral (Tr (F wedge F) ) = 0 for all gauge field configurations. This predicts thetaQCD = 0 exactly, dₙ = 0, and the absence of the axion without any new fields. Third, the Z3 triality of SO (8) accommodates three quark colours; quark masses follow the same phiᵏ hierarchy as leptons with the up quark at k=3 to 0. 2% and isospin doublet spacings Deltaₖ in 2, 5, 7 — all Fibonacci-related integers. Fourth, the QCD confinement scale is derived as LambdaQCD = Z3 × mₑ × phiM = 305 MeV (8% from PDG), where M=11 is the Hopf factor. Fifth, the CMB temperature parity ratio RTT = (6pi−1) / (6pi+1) ² = 0. 8086 is derived from RP4 antipodal geometry with Z3 suppression, agreeing with Planck 2018 at 0. 05 sigma. The integer 23 = Nco + 1 is the common origin of the cosmological constant (via betacoh = 6cos (pi/23) ), the proton mass (via the colour-phase reflection j → 23−j), and the fourth-generation lepton prediction (k₄th = 23).