2002/06/30 by Stefano Ansoldi, Eduardo Guendelman, Eduardo I. Guendelman +1
Physics and Astronomy · #Cosmology and Gravitation Theories #Dark Matter and Cosmic Phenomena #Quantum Electrodynamics and Casimir Effect #hep-th
paper · pdf · doi:10.1088/1126-6708/2003/09/044
published as JHEP 0309 (2003) 044 · Extended content, some mistakes amended 21 pages, JHEP 3 class
openalex publication_date 2003/09/18 · arxiv created 2003/10/01 · arxiv updated 2009/11/30 · openalex created_date 2016/06/24 · openalex updated_date 2026/07/28
Small fluctuations around a constant electric or constant magnetic field F are analyzed in a theory with pseudo scalar [phi] with a coupling g[phi]F~F. It is found that a magnetic external field leads to mass generation for the small perturbations, while an electric field suffers from a tachyonic mass generation in the case in which the field strength is higher than a critical value (related to the pseudo scalar mass). The vacuum energy can be exactly evaluated and it is found that an imaginary part is present when the external electric field exceeds its critical value.