compared with previously reported results. We also compute the force between the charge and the $\theta$-boundary by two different methods, using the energy momentum tensor approach and the interaction energy calculated via the GF. The infinitely straight current-carrying wire is also analyzed.
author:
- 'A. Martín-Ruiz'
- 'M. Cambiaso'
- 'L. F. Urrutia'
title: 'Green’s function approach to Chern-Simons extended electrodynamics: an effective theory describing topological insulators'
---

Introduction
============

The relevance of Chern-Simons (CS) forms [@Chern:1974ft] in several branches of theoretical physics is well accounted for. In quantum field theory in regards to anomalies [@ABJ] they played a key role and in particle physics they proved important as well [@Peccei:1977hh; @'tHooft:1986nc; @Wilczek:1987mv]. In general relativity they also enjoy a prominent position as clearly reviewed in [@Zanelli:2012px]. Further studies involve its uses in topological quantum field theory [@Witten:1988ze], topological string theory [Marino:2004uf]{} and as a quantum gravity candidate [@Bonezzi:2014nua].

In general, CS forms are amenable for capturing topological features of the physical system they describe, which is why in the last decade their importance has also become apparent in the field of condensed matter physics for describing what came to be known as topological phases. von Klitzing’s discovery of the 