Quantum Gravity from the Trit: The Graviton as Spin-2 Compact Phase, the Equivalence Principle, and Finiteness from T³ Discreteness

The Trit framework [1,2] derives the Standard Model parameters and quantum mechanics from the axiom T = {-1,0,+1}. This paper extends the derivation to quantum gravity. The graviton is identified as the massless excitation of the symmetric Trit sector S_{μν}, carrying a compact phase ϕ_g ∈ S² ⊂ (S²)³. The linearised Einstein equations follow from varying the Trit symmetric action, deriving □h̄_{μν} = -16πG T_{μν} without postulate. Exactly two graviton polarisations emerge from the winding-free symmetric constraint. The equivalence principle — gravitational mass equals inertial mass — is derived from the universality of S_{μν} coupling to all 27 T³ matter fields. The gravitational Born rule P(GW at r₀) = ∫_{S²}|h_{μν}|^2 dμ/(4π) has the same structure as the quantum mechanical Born rule but with integration over S² rather than (S²)³. Finiteness of quantum gravity in this framework follows from the discreteness of T³: the lattice spacing a_Trit = ħc/M_Trit = 2.45 × 10^{-33} m provides a natural UV cutoff at M_Trit = 8.04×10^{16} GeV < M_P, below the Planck scale where standard GR loops diverge. The three physical sectors — matter (spin-½), gauge (spin-1), gravity (spin-2) — are unified by the same compact phase mechanism with integration domains (S²)³, S¹, and S² respectively.