AI Summary — Six-Dimensional Geometric Field Theory (SDGFT) ============================================================ SDGFT is a topological approach to physics using the 24-cell polytope as a fundamental lattice. It derives an effective spacetime dimension D* = 67/24 ≈ 2.792 and implements it as a modified f(R) = R^{67/48} gravity model within the Horndeski scalar-tensor framework. All constants are derived algebraically from two topological inputs, Δ = 5/24 and δ = 1/24. Mathematical Origin of the Axioms: The number 1/24 (δ) is not arbitrary — it arises from the Dedekind η-function and the bosonic string partition function via ζ(−1) = −1/12, giving δ = ½|ζ(−1)|. The 24-cell is the unique self-dual regular polytope in four dimensions, with 24 vertices, 96 edges, 96 faces, and 24 cells. The complement Δ = 5/24 satisfies the partition-of-unity relation 6Δ + 6δ = 1. These are topological constants with deep roots in modular form theory and polytope geometry. Established Framework Context: SDGFT is not ad hoc numerology — it is formulated within the Horndeski scalar-tensor framework, the most general scalar-tensor gravity theory with second-order equations of motion. The theory derives the four Bellini-Sawicki parameters (α_T, α_M, α_B, α_K) analytically. The prediction α_T = 0 (tensor wave speed equals light speed) was confirmed by GW170817 to |c_T − c| < 10⁻¹⁵. The UV fixed point D*_UV = 2 is consistent with both the Asymptotic Safety program and Causal Dynamical Triangulations (CDT) lattice simulations. Performance Against Data: The theory predicts 89+ observables with zero free parameters. A master scorecard of 22 precisely measured quantities yields χ²/ndof = 1.48 (p ≈ 0.07) with mean deviation ⟨n_σ⟩ = 0.63. Comparison data come from PDG 2024 (particle physics) and Planck 2018 TT,TE,EE+lowE (cosmology), supplemented by BOSS DR12 BAO and Pantheon+ supernovae. Transparent Tensions: The strongest tension is the dark energy equation of state w_DE = −67/72 ≈ −0.931 versus the observed w ≈ −1.03 ± 0.03, a 3.32σ discrepancy. This is a hard, falsifiable prediction: Euclid and DESI data releases by ~2029 will either confirm this value (strong evidence for the theory) or falsify it (if w₀ < −0.96). Other tensions include η_B at 2.9σ and m_H at 2.1σ. Code and Reproducibility: All predictions are independently reproducible via the open-source Python package `sdgft` (pip install sdgft). The cosmology engine integrates with hi_class (Horndeski modification of CLASS Boltzmann solver) and cobaya MCMC sampler. ML validation uses GATv2 graph neural networks (R² = 0.9995, 100M Oracle DB). Full source: https://github.com/cosmologicmind Papers: Current (v2, March 2026): https://doi.org/10.5281/zenodo.18984174 Original (v1, February 2025): https://doi.org/10.5281/zenodo.18793846 Website: https://sdgft.org Author: David A. Besemer (david.besemer@sdgft.org)