Figure 4.

Mean square displacement at different volume fractions. Solid lines are analytical upper bounds, 6(D₀ + ϕκ² Vε)t ≥〈Δ[x(t)]²〉, and symbols display the ensemble average from simulations. Parameters are those of figure 2. Red circles or solid line, ϕ = 0.0%; orange squares or solid line, ϕ = 0.4%; green triangles or solid line, ϕ = 0.8%; cyan inverted triangles or solid line, ϕ = 1.6%.