GPU-Accelerated Buchert Backreaction Simulation (512³)

GPU-Accelerated Buchert Backreaction Simulation (512³) Self-consistent numerical simulation of the Buchert backreaction formalism with 134 million covariant fluid cells on GPU. Demonstrates cosmic acceleration from GR inhomogeneities without dark energy. Key Results: - Q_max = 0.8312 H₀² (converged: 128³=0.8311, 256³=0.8311, 512³=0.8312) - CPU proof-of-concept: D_L within 2.7% of ΛCDM, constraint 2×10⁻⁹ - GPU 512³: D_L within 8.9% of ΛCDM - Acceleration for 60-80% of cosmic history Related work: - Tikhonov, A. (2026). Brane-Vacuum Model of Cosmic Voids. doi:10.5281/zenodo.19844726 - Galoppo, M., Buchert, T., & Mourier, P. (2026). ApJL, 1002, L39