Cluster persistence of two-dimensional soap froth.

We report on the persistence decay of cell clusters in dynamical simulation of two-dimensional soap-froth as a function of the cluster volume fraction. Both slow gas diffusion and fast dynamical topological processes between cells are incorporated in the simulation. While the simulation yields decay rate in good agreement with two-dimensional soap-froth experiment, it shows a faster decay in comparison to measurements and calculations of persistence in other curvature-driven systems. The fraction of individual cells that contain persistent area also decays due to significant cell movements, confirming that the neighbor swapping T1 topological transition is important in froth coarsening.