The current density in quantum electrodynamics in external potentials

Autor(en)

Jan Schlemmer, Jochen Zahn

Abstrakt

We review different definitions of the current density for quantized fermions in the presence of an external electromagnetic field. Several deficiencies in the popular prescription due to Schwinger and the mode sum formula for static external potentials are pointed out. We argue that Dirac's method, which is the analog of the Hadamard point-splitting employed in quantum field theory in curved space-times, is conceptually the most satisfactory. As a concrete example, we discuss vacuum polarization and the stress-energy tensor for massless fermions in 1+1 dimension. Also a general formula for the vacuum polarization in static external potentials in 3 + 1 dimensions is derived.

Organisation(en)

Mathematische Physik

Externe Organisation(en)

Universität Leipzig

Journal

Annals of Physics

Band

359

Seiten

31-45

Anzahl der Seiten

15

ISSN

0003-4916

DOI

https://doi.org/10.1016/j.aop.2015.04.006

Publikationsdatum

08-2015

Peer-reviewed

Ja

ÖFOS 2012

103036 Theoretische Physik

Schlagwörter

ASJC Scopus Sachgebiete

Allgemeine Physik und Astronomie

Link zum Portal

https://ucrisportal.univie.ac.at/de/publications/2a43fdc6-2d4e-4662-907f-999dac0d9755