UNIVERSAL DISTANCE RATIOS FOR INTERACTING 2-DIMENSIONAL POLYMERS

We present the hypothesis that at the theta-temperature of a single interacting polymer in two dimensions, a particular combination of universal distance amplitude ratios is given exactly by a simple formula in terms of critical indices only. This generalizes a similar claim for noninteracting self-avoiding walks,which was derived from conformal invariance considerations. We support our hypothesis with a series analysis of interacting self-avoiding walks on the square lattice, high-precision simulations of interacting self-avoiding walks on the Manhattan lattice at the exact theta-point and similar simulations of interacting trails on the square lattice.