Z-Geometric Dynamics (ZGD) predicts that the matter distribution in the Universe produces a drag suppression effect on the local Hubble parameter through the “matter wrinkling” mechanism. This overall drag suppression picture has received various indirect support from galactic rotation curves and cosmological scales, but whether it manifests as an observable directional dependence in the nearby Universe—i. e. , whether directions with denser matter systematically exhibit lower local Hubble constants—has not been independently answered. Using the Cosmicflows-4 galaxy group catalog (38, 065 groups, redshift z<0. 02), we assign galaxy groups to all-sky pixels, measure the local Hubble constant in each pixel, and count the group surface density as a proxy for matter density. We directly test the correlation between the two. The results show a statistically significant negative correlation between the local Hubble constant and group surface density (Spearman r=-0. 13, p=1. 2×10^-10; Pearson r=-0. 14, p=1. 7×10^-12), consistent with the ZGD prediction—directions with denser matter systematically exhibit lower local Hubble constants. This constitutes the first statistical evidence for the ZGD matter wrinkling mechanism from nearby galaxy group data. We also discuss the influence of peculiar velocities and survey systematics, and outline future tests aligned with the falsification checklist of Paper II.
Meng Fanlei (Tue,) studied this question.