# Phase of the fermion determinant in QED_3 using a gauge invariant lattice regularization

Research paper by Nikhil Karthik, Rajamani Narayanan

Indexed on: 12 Jun '15Published on: 12 Jun '15Published in: High Energy Physics - Theory

#### Abstract

We use canonical formalism to study the fermion determinant in different three dimensional abelian gauge field backgrounds that contain non-zero magnetic and electric flux in order to understand the non-perturbative contributions to the parity-odd and parity-even parts of the phase. We show that a certain phase associated with free fermion propagation along a closed path in a momentum torus is responsible for the parity anomaly in a background with non-zero electric flux. We consider perturbations around backgrounds with non-zero magnetic flux to understand the structure of the parity-breaking perturbative term at finite temperature and mass.