We adopt the general formalism for analyzing evolution of gaussian states ofquantized fields in time-dependent backgrounds in the Schrodinger picture(presented in detail in arXiv:0708.1233 and 0708.1237) to study the example ofa spatially uniform electric field background (in a time-dependent gauge) whichis kept turned on for a finite duration of time. In particular, we study the\emph{time-dependent} particle content, defined in terms of the concept ofinstantaneous eigenstates, and describe how it captures the time evolution ofthe quantized field modes. The actual particle creation process occurs over arelatively short interval in time, and the particle content saturates ratherquickly. We also compare the \emph{power spectrum} of the field modes, computedin the asymptotic limit, with the corresponding situation in a cosmological deSitter background. Particle creation under the influence of a spiked electricfield localized in time, as a particular limiting case of the above generalmodel, is also considered.
展开▼
