Ballesteros, H.G.Fernández Pérez, Luis AntonioMartín Mayor, VíctorMuñoz Sudupe, Antonio2023-06-202023-06-201998-11-260370-269310.1016/S0370-2693(98)01100-9https://hdl.handle.net/20.500.14352/60079© 1998 Elsevier Science B.V. All rights reserved. We thank Giorgio Parisi for an encouraging discussion on the feasibility of this work. We are also grateful to Juan Jesús Ruiz-Lorenzo for many interesting discussions and comments. This work has been partially supported by CICyT (contracts AEN97-1708, AEN97-1693) . The simulations have been carried out in the RTNN machines at Zaragoza and Complutense de Madrid Universities.Using Finite-Size Scaling techniques, we numerically show that the first irrelevant operator of the lattice λΦ^(4) theory in three dimensions is within errors completely decoupled at λ = 1.0. This interesting result also holds in the Thermodynamical Limit, where the renormalized coupling constant shows an extraordinary reduction of the scaling-corrections when compared with the Ising model. It is argued that Finite-Size Scaling analysis can be a competitive method for finding improved actions.engjournal articlehttp://doi.org/10.1016/S0370-2693(98)01100-9http://www.sciencedirect.com/open access5351-73Antiferromagnetic RP(2) modelAsymptotically free theoriesMonte-Carlo simulationsCritical exponentsRenormalization-group3 dimensionsField-theoryPercolationDynamics.Física (Física)Física-Modelos matemáticos22 Física