New method for growing branched polymers and large percolation clusters below pc

We propose a new Monte Carlo method for generating large branched polymers; it is based on enrichment of percolation clusters below pc. We find that one must take care to distinguish two different ensemble averages: one at constant mass s and the other at constant chemical distance l. For constant s, we obtain clusters belonging to the universality class of lattice animals, while for constant l we get topologically one-dimensional structures for all d.