Adaptive Optimization of Wave Functions for Lattice Field Models

Abstract

The accuracy of Green Function Monte Carlo (GFMC) simulations can be greatly improved by a clever choice of the approximate ground state wave function that controls configuration sampling. This trial wave function typically depends on many free parameters whose fixing is a non trivial task. Here, we discuss a general purpose adaptive algorithm for their non-linear optimization. As a non trivial application we test the method on the two dimensional Wess-Zumino model, a relativistically invariant supersymmetric field theory with interacting bosonic and fermionic degrees of freedom.

12 pages, 5 EPS figures, Contribution to the Proceedings of the "Quantum Monte Carlo" meeting (Trento, Italy, July 3-6, 2001)