FIG. 2. Top panel: global 1D momentum distribution in the PIC simulation of a shear force acting parallel to the mean magnetic field B 0 , exhibiting broadening by bulk flows. Bottom panel: t Þ relative to the initial change of the Casimir momenta Δ p c; χ ð 0 Þ for the local coarse-grained distribution (solid lines) value p c; χ ð and for the global distribution (dotted lines); varying χ values are indicated by colors in the legend. For reference, the relative increase in the average momentum Δ h p ið t Þ = h p ið 0 Þ is shown by the black dashed