Strong Scalar QED in Inhomogeneous Electromagnetic Fields

Abstract

Strong QED has attracted attention recently partly because many astrophysical phenomena have been observed to involve electromagnetic fields beyond the critical strength for electron-positron pair production and partly because terrestrial experiments will generate electromagnetic fields above or near the critical strength in the near future. In this talk we critically review QED phenomena involving strong external electromagnetic fields. Strong QED is characterized by vacuum polarization due to quantum fluctuations and pair production due to the vacuum instability. A canonical method is elaborated for pair production at zero or finite temperature by inhomogeneous electric fields. An algorithm is advanced to calculate pair production rate for electric fields acting for finite periods of time or localized in space or oscillating electric fields. Finally, strong QED is discussed in astrophysics, in particular, strange stars.

Perturbation theory for metastable states of the Dirac equation with quadratic vector interaction

“…In [6] the pair production rate was also calculated from the line width of the lowest state finding a perfect agreement, for the linear potential and in the range of validity of the first perturbation order, with the results obtained from the imaginary part of the Schwinger effective action, [9]. It should also be noticed that the QED results on the pair production for fermions in non constant electric fields are not yet so sound, although interesting proposals can be found in literature, (see [10] for an up to date review). We can finally remark that relativistic models with power-law potentials, in three space dimensions and in spherical geometry, have been used in the study of composite systems like Quarkonium, in order to determine the mass spectrum of some meson families, [11].…”