Ação de Euler–Heisenberg generalizada: para férmions acoplados a vetor e pseudovetor

Abstract

In this dissertation, a comprehensive analysis of an one-loop exact Euler-Heisenberg effective action is presented, specifically tailored for fermions coupled simultaneously to both a vector field and a axial vector field. Utilizing the proper-time representation alongside the Weisskopf-Landau method, which corresponds to the implementation of Zeta function regularization, to derive the results. The chosen approach involves classifying some parameter subspaces and arriving at an exact solution within the physically relevant subspace, while focusing on an approximation of quasi-static field configurations. Afterwards, following an assessment on the consistency of the findings, the implications of chiral anomaly are investigated and particle pair creation rates are calculated under different assumptions. Furthermore, the effective action framework is applied to a toy model of the early universe, positing that a massive pseudo-vector field could be instrumental in baryogenesis, thereby accounting for the observed baryonic asymmetry in the present-day universe as shown by data from the Planck Collaboration. This analysis includes estimates of the necessary field strength and its current value, highlighting the potential viability of the proposed model.