English (United Kingdom)

https://curated-unify.zendy.io/wp-json/zendy-region/v1/featured_content/oa?rat=en

https://curated-unify.zendy.io/wp-json/zendy-region/v1/highlighted_journal/

Global: Zendy Plus annual

Presents the access of premium content as premium feature

Premium Content

Presents the keyphrase highlighting as premium feature

Keyphrase Highlighting

Presents the summarisation as premium feature

Summarisation

Insights

Presents the pdf analysis as premium feature

PDF Analysis

Presents the zaia usage as premium feature

ZAIA

Global: Zendy Plus monthly

Global: Zendy Tools annual

Global: Zendy Tools monthly

Global: Zendy Free Plan

We carry out the canonical quantization of the electromagnetic field inarbitrary $\xi$-gauge and compute its propagator. In this way we fill a gap inthe literature and clarify some existing confusion about Feynman $i\epsilon$prescription for the propagator of the electromagnetic field. We also discussthe BRST quantization and investigate the apparent singularities present in thetheory when the gauge parameter $\xi$ takes the value -1. We find that this isa mere artifact due to the choice of basic modes and show that in theappropriate basis the commutation relations and the BRST transformation are, infact, independent of the gauge parameter. The latter only appears as thecoefficient of a BRST exact term in the Hamiltonian, which constitutes anextremely simple proof of the independence of any physical process on the gaugeparameter $\xi$.

Canonical quantization of the electromagnetic field in arbitrary $\xi$-gauge