Dark Matter from a Second Warped Throat: Gravitational Freeze‑In in the DBQTM Framework

Abstract We extend the Dual-Brane Quantum Tunneling Model (DBQTM) to incorporate dark matter through a multi-throat compactification on a Calabi--Yau manifold. While the first Klebanov--Strassler throat (K₁=203, M₁=17, kd₁ 375) generates the observed cosmological constant via vacuum energy suppression, a second throat (K₂=39, M₂=35, kd₂ 35) produces a natural dark matter candidate: the lightest scalar glueball of the confined gauge theory, with mass mDM = k\, e^-kd₂ 133~GeV. Dark matter is produced via UV-dominated gravitational freeze-in through zero-mode graviton exchange, yielding the observed relic abundance DM h² = 0. 12 for an inflationary Hubble rate Hᵢnf 10^13~GeV, which predicts a tensor-to-scalar ratio r 0. 001--0. 01 testable by LiteBIRD and CMB-S4. The dark matter is absolutely stable on cosmological timescales (1. 6 10^32~yr) and undetectable via direct detection (SI 10^-98~cm²). Both the cosmological constant and the dark matter mass are determined by five discrete parameters (K₁, M₁, K₂, M₂, gₛ), with k fixed by the RS geometry and gₛ fixed in the first throat to reproduce the observed _~DBQTM-Paper1. The cross-prediction kd₁/kd₂ = K₁ M₂/ (K₂ M₁) is verified exactly. The tadpole constraint K₁ M₁ + K₂ M₂ = 4816 requires a Calabi--Yau with Euler characteristic 115, 584. 2. 0: Adds perturbative brane backreaction analysisconfirming RS consistency (BR10^-34, Appendix~C) and detailed gravitational freeze-in derivation includingwarped lifetime (2. 910^33~yr) and decay branchingfractions (Appendix~D). Core predictions unchanged. inflation, Randall--Sundrum, Klebanov--Strassler, Starobinsky, warped extra dimensions, dark matter, string cosmology