Dual Spacetime Reaction (DRR-v3.2): Scalar-Tensor Response to Baryon Asymmetry, S8 Tension, and Cluster Dynamics.

We present the Dual Spacetime Reaction (DRR-v3.2) framework, an effective scalar-tensor theory in which the cosmic baryon asymmetry ηB≈6×10−10 sources a scalar field coupled to baryonic matter. An exponential density-dependent screening ensures Solar System compliance while producing deviations in low-density regions, alleviating the S8 tension and predicting lensing-dynamics mass ratios Mdyn/Mlens≈0.98−0.99.