Fig. 4. Autocorrelation functions of shear stress τ₂.

a Spatial autocorrelation map $⟨C_{{\tau }_2}\left(r,\theta \right)⟩$ of coarse-grained shear stress τ₂(α), 〈 ⋯ 〉 denotes ensemble average over 100 configurations and different polarized angles α. b Cuts of $⟨C_{{\tau }_2}\left(r,\theta \right)⟩$ along θ = 0 and θ = π/4, and their azimuthal averaged autocorrelation function $⟨{\overline{C}}_{{\tau }_2}\left(r\right)⟩$. The error bars represent the standard errors. The black dashed line indicates a power law fit of $⟨{\overline{C}}_{{\tau }_2}\left(r\right)⟩$ for r > 6d.