Fermion-induced effective action in the presence of a static inhomogeneous magnetic field

Pasipoularides, P

dc.contributor.author	Pasipoularides, P	en
dc.date.accessioned	2014-03-01T01:16:35Z
dc.date.available	2014-03-01T01:16:35Z
dc.date.issued	2001	en
dc.identifier.issn	0556-2821	en
dc.identifier.uri	https://dspace.lib.ntua.gr/xmlui/handle/123456789/14098
dc.subject	Effective Action	en
dc.subject	Magnetic Field	en
dc.subject	Metastable State	en
dc.subject	Landau Level	en
dc.subject.classification	Astronomy & Astrophysics	en
dc.subject.classification	Physics, Particles & Fields	en
dc.subject.other	analytic method	en
dc.subject.other	article	en
dc.subject.other	Fourier transformation	en
dc.subject.other	magnetic field	en
dc.subject.other	molecular dynamics	en
dc.subject.other	phase separation	en
dc.subject.other	quantum theory	en
dc.title	Fermion-induced effective action in the presence of a static inhomogeneous magnetic field	en
heal.type	journalArticle	en
heal.identifier.primary	10.1103/PhysRevD.64.105011	en
heal.identifier.secondary	http://dx.doi.org/10.1103/PhysRevD.64.105011	en
heal.identifier.secondary	105011	en
heal.language	English	en
heal.publicationDate	2001	en
heal.abstract	We present a numerical study of the fermion-induced effective action in the presence of a static inhomogeneous magnetic field for both (3+1)- and (2+1)-dimensional QED using a novel approach. This approach is appropriate for cylindrically symmetric magnetic fields with a finite magnetic flux Φ. We consider families of magnetic fields, dependent on two parameters: a typical value Bm for the field and a typical range d. We investigate the behavior of the effective action for three distinct cases: (1) keeping Φ (or Bmd2) constant and varying d, (2) keeping Bm constant and varying d, and (3) keeping d constant and varying Φ (or Bmd2). We note an interesting difference in the limit d→+∞ (case 2) between smooth and discontinuous magnetic fields. In the strong field limit (case 3) we also derive an explicit asymptotic formula for the (3+1)-dimensional action. We study the stability of the magnetic field and show that magnetic fields of the type we examine remain unstable, even in the presence of fermions. In the appropriate regions we check our numerical results against the Schwinger formula (constant magnetic field), the derivative expansion, and the numerical work of Bordag and Kirsten. The role of the Landau levels in the effective action and the appearance of metastable states for a large magnetic flux are discussed in the Appendixes. ©2001 The American Physical Society.	en
heal.publisher	AMERICAN PHYSICAL SOC	en
heal.journalName	Physical Review D	en
dc.identifier.doi	10.1103/PhysRevD.64.105011	en
dc.identifier.isi	ISI:000172074100044	en
dc.identifier.volume	64	en
dc.identifier.issue	10	en