Sonoluminescence: Bogolubov coefficients for the QED vacuum of a time-dependent dielectric bubble

Abstract

We extend Schwinger's ideas regarding sonoluminescence by explicitly calculating the Bogolubov coefficients relating the QED vacuum states associated with changes in a dielectric bubble. Sudden (non-adiabatic) changes in the refractive index lead to an efficient production of real photons with a broadband spectrum, and a high-frequency cutoff that arises from the asymptotic behaviour of the dielectric constant.

4 pages, RevTeX, 2 figures (.eps file) included with graphics.sty. Major revisions: physical scenario clarified, additional numerical estimates