Derivation of effective field theories
Abstract
A general self-consistency approach allows a thorough treatment of the corrections to the mean-field approximation (MFA). The natural extension of standard MFA with the help of a cumulant expansion leads to a new point of view on the effective field theories. The proposed approach can be used for a systematic treatment of fluctuation effects of various length scales and, perhaps, for the development of a new coarse graining procedure. We outline and justify our method by some preliminary calculations. Results are given for the critical temperature and the Landau parameters of the -theory -- the field counterpart of the Ising model. An important unresolved problem of the modern theory of phase transitions -- the problem for the calculation of the true critical temperature, is considered within the framework of the present approach. A comprehensive description of the ground state properties of many-body systems is also demonstrated.
Cite
@article{arxiv.0808.0937,
title = {Derivation of effective field theories},
author = {Dimo I. Uzunov},
journal= {arXiv preprint arXiv:0808.0937},
year = {2009}
}