Canonical Demon Monte Carlo Renormalization Group

TL;DR

This paper introduces a Monte Carlo renormalization group method using canonical demons to accurately compute renormalized couplings in lattice models, reducing systematic errors present in previous microcanonical approaches.

Contribution

It presents a novel Monte Carlo RG technique employing canonical demons, improving accuracy over prior microcanonical methods for lattice spin and gauge models.

Findings

Numerical results for the O(3) nonlinear sigma-model demonstrate the method's effectiveness.

The approach reduces systematic errors in small volume calculations.

Applicable to various lattice models, including spin and gauge theories.

Abstract

We describe a method to compute renormalized coupling constants in a Monte Carlo renormalization group calculation. It can be used, e.g., for lattice spin or gauge models. The basic idea is to simulate a joint system of block spins and canonical demons. Unlike the Microcanonical Renormalization Group of Creutz et al. it avoids systematical errors in small volumes. We present numerical results for the O(3) nonlinear sigma-model.