Physical Review E
Momentum-shell renormalization-group flow from simulation
A. Tröster
Abstract
Our recently developed Fourier Monte Carlo algorithm permits a nonperturbative calculation of momentum-shell renormalization-group flows by simulation which despite its apparent simplicity is illustrative both numerically as well as conceptually interesting. We study the example of a varphi(4) model with long-range lattice interaction. For this model we show that the topology of the renormalization flow is globally accessible in a particularly convenient way. The nontrivial fixed point of Wilson-Fisher type is observed its accompanying critical exponents are numerically determined from fitting its surrounding flow pattern to a linearized renormalization-group transformation. The results are compared to those obtained from perturbation theory, -expansion and earlier Monte Carlo simulations. Application of our method is also expected to be rewarding in other models with long-range interactions.