Cosmological Predictions of Six-Dimensional Geometric Field Theory: Numerical Implementation in hi_class and Comparison with Planck 2018 Data

We present the first numerical implementation of the cosmological sector of Six-Dimensional Geometric Field Theory (SDGFT) within the Horndeski gravity Boltzmann solver hi_class. SDGFT derives all cosmological parameters from two topological constants: Delta=5/24 and delta=1/24. Our model achieves a total chi^2=12,769.3 against Planck 2018 data, an improvement of Delta_chi^2=-35.9 over LambdaCDM with zero free parameters. The theory predicts w_DE≈-0.931, r=0.013, and an isocurvature fraction beta_iso=1/36, providing sharp falsification criteria for upcoming experiments like Euclid, LiteBIRD, and CMB-S4.