Completing the DBQTM: Inflation from a Third Warped Throat

Abstract We complete the Dual-Brane Quantum Tunneling Model (DBQTM) by introducing a third Klebanov--Strassler throat as the inflationary sector. In the companion papers~DBQTM-Paper1, DBQTM-Paper2, two warped throats on the same Calabi--Yau manifold were shown to generate the cosmological constant (Throat~1: K₁=203, M₁=17, kd₁ 375) and dark matter (Throat~2: K₂=39, M₂=35, kd₂ 35, mDM 133~GeV). A shallow third throat with (K₃, M₃) = (3, 27) and kd₃ 3. 5 provides a GUT-scale IR sector at ₈ₑ, ₃ 6. 5 10^15~GeV. The K\"ahler modulus of this throat, stabilized via the KKLT mechanism with SU (27) gaugino condensation, naturally produces a Starobinsky-like -attractor inflationary potential (= 1), predicting nₛ = 0. 964 and r = 0. 004, both consistent with Planck and testable by LiteBIRD and CMB-S4. The scalaron decay produces a reheating temperature TRH 2. 5 10⁹~GeV, precisely in the range required for gravitational freeze-in production of the dark matter candidate in Throat~2. All three cosmological sectors --- dark energy, dark matter, and inflation --- are thus determined by seven discrete flux integers (K₁, M₁, K₂, M₂, K₃, M₃, gₛ) and one continuous parameter (k/MPl), with verifiable cross-predictions linking the inflationary observables to the dark matter abundance.