Low-temperature expansion and perturbation theory in 2D models with unbroken symmetry: a new approach

Abstract

A new method of constructing a weak coupling expansion of two dimensional (2D) models with an unbroken continuous symmetry is developed. The method is based on an analogy with the abelian XY model, respects the Mermin-Wagner (MW) theorem and uses a link representation of the partition and correlation functions. An expansion of the free energy and of the correlation functions at small temperatures is performed and first order coefficients are calculated explicitly. They are shown to coincide with the results of the conventional perturbation theory. We discuss an applicability of our method to analysis of uniformity of the low-temperature expansion.

arXiv comment20 pages, Latex, 1 fig. Typo in Eq.(46) which led to wrong result is corrected. Agreement with conventional method is recovered

References in corpus (6)

• Super-Instantons and the Reliability of Perturbation Theory in Non-Abelian Models
• Super-Instantons in Gauge Theories and Troubles with Perturbation Theory
• Questionable and unquestionable in the perturbation theory of non-Abelian models
• Questionable Arguments for the Correctness of Perturbation Theory in Non-Abelian Models
• Comment on "Superinstantons and the Reliability of Perturbation Theory in Non-Abelian Models"
• Two-dimensional dynamics of QCD_3

Cited by in corpus (6)

• Duals of U(N) LGT with staggered fermions
• Dual formulations of Polyakov loop lattice models
• Plaquette representation for 3D lattice gauge models: I. Formulation and perturbation theory
• Dual formulations of non-abelian spin models: local representation and low-temperature asymptotics
• Finite density 2d O(3) sigma model: dualization and numerical simulations
• Monopoles in the Plaquette Formulation of the 3D SU(2) Lattice Gauge Theory