Renormalization Group Therapy

Abstract

We point out a general problem with the procedures commonly used to obtain improved actions from MCRG decimated configurations. Straightforward measurement of the couplings from the decimated configurations, by one of the known methods, can result into actions that do not correctly reproduce the physics on the undecimated lattice. This is because the decimated configurations are generally not representative of the equilibrium configurations of the assumed form of the effective action at the measured couplings. Curing this involves fine-tuning of the chosen MCRG decimation procedure, which is also dependent on the form assumed for the effective action. We illustrate this in decimation studies of the SU(2) LGT using Swendsen and Double Smeared Blocking decimation procedures. A single-plaquette improved action involving five group representations and free of this pathology is given.

18 pages, 9 figures, 9 tables

References in corpus (1)

• RG decimation-based approach to confinement and computation on coarser lattices

Cited by in corpus (5)

• Inverse Monte-Carlo determination of effective lattice models for SU(3) Yang-Mills theory at finite temperature
• Equilibrium criterion and effective spin models for finite temperature gauge theories
• Improving the improved action
• String tension and removal of lattice coarsening effects in Monte Carlo Renormalization Group
• Improved actions and lattice coarsening effects in MCRG studies in SU(2) LGT