Random Walks with Long-Range Self-Repulsion on Proper Time
  We introduce a model of self-repelling random walks where the short-range interaction between two elements of the chain decreases as a power of the difference in proper time. Analytic results on the exponent $\nu$ are obtained. They are in good agreement with Monte Carlo simulations in two dimensions. A numerical study of the scaling functions and of the efficiency of the algorithm is also presented. 
S. Caracciolo, G. Parisi and A. Pelissetto