O formalismo Gauge Unfixing aprimorado no modelo Sigma Não Linear

Abstract

In this work we investigate the canonical structure of the O(N) Sigma Nonlinear Model (MSNL), which is originally a second class system using the improved gauge unfixing (GU) method. This investigation aimed to analyze the efficiency and advantages of the improved GU compared to the usual GU, showing it to be a good alternative for a constrained conversion method. By applying it to MSNL, we were able to directly modify the system’s original phase space variables without the need to implement extra variables or fields, in order to make it first class and consequently gauge invariant. At the end of the process we obtained the new respective field variables, Lagrangian and Hamiltonian gauge invariant. When comparing with the generalized Dirac parentheses of the same model, we were able to obtain the same results, thus proving to be a method with a consistent structure and a better alternative compared to the usual GU.