KRAMERS EQUATION SIMULATION ALGORITHM .2. APPLICATION TO THE GROSS-NEVEU MODEL

We continue the investigation on the applications of the Kramers equation to the numerical simulation of field theoretic models. In a previous paper we described the theory and proposed various algorithms. Here, we compare the simplest of them with the hybrid Monte Carlo algorithm studying the two-dimensional lattice Gross-Neveu model. We used a Symanzik-improved action with dynamical Wilson fermions. Both the algorithms allow for the determination of the critical mass. Their performances in the definite phase simulations are comparable with the hybrid Monte Carlo algorithm. For the two methods, the numerical values of the measured quantities agree within the errors and are compatible with the theoretical predictions; moreover, the Kramers algorithm is safer from the point of view of numerical precision.