Self-avoiding random walks: Some exactly soluble cases

Abstract

We use the exact renormalization group equations to determine the asymptotic behavior of long self-avoiding random walks on some pseudolattices. The lattices considered are the truncated 3-simplex, the truncated 4-simplex, and the modified rectangular lattices. The total number of random walks Cn, the number of polygons Pn of perimeter n, and the mean square end to end distance 〈R2n〉 are assumed to be asymptotically proportional to μnnγ−1, μnnα−3, and n2ν respectively for large n, where n is the total length of the walk. The exact values of the connectivity constant μ, and the critical exponents λ, α, ν are determined for the three lattices. We give an example of two lattice systems that have the same effective nonintegral dimensionality 3/2 but different values of the critical exponents γ, α, and ν.