LARGE-CELL RENORMALIZATION GROUP FOR THE BACKBONE PROBLEM IN PERCOLATION

The authors give a position-space renormalisation group treatment of percolation backbones. Introducing a ghost field which couples only to backbone bonds, this problem is placed on the same conceptual footing as pure percolation. This framework allows one to apply scaling arguments to obtain all the exponents from the scaling powers yp and yh; these in turn are calculated from the renormalisation group using large cells.