An Optimised Perturbation Expansion For a Global O(2) Theory

TL;DR

This paper applies an optimized perturbation method, the linear delta-expansion, to analyze phase transitions in a Higgs sector with continuous symmetry, demonstrating its effectiveness and simplifications for non-perturbative problems.

Contribution

It introduces a simplified version of the linear delta-expansion method for studying phase transitions in theories with large couplings and continuous symmetries.

Findings

Successful application of the linear delta-expansion to Higgs sector phase transitions

Demonstration of method's flexibility and potential for non-perturbative analysis

Simplification of the perturbation expansion without loss of accuracy

Abstract

We use an optimised perturbation expansion called the linear delta-expansion to study the phase transition in a Higgs sector with a continuous symmetry and large couplings. Our results show how to use this non-perturbative method successfully for such problems. We also show how to simplify the method without losing any flexibility.