Sonoluminescence and the QED vacuum

TL;DR

This paper extends Schwinger's quantum-vacuum approach to sonoluminescence, deriving spectral estimates and emphasizing the importance of refractive index change timescales, proposing a modified dynamical Casimir effect model.

Contribution

It introduces a refined model linking QED vacuum changes to sonoluminescence, incorporating physical constraints and a new perspective on the dynamical Casimir effect.

Findings

Spectral and energy estimates proportional to refractive index change volume

Revealed importance of refractive index change timescale

Proposed a modified dynamical Casimir effect model

Abstract

In this talk I shall describe an extension of the quantum-vacuum approach to sonoluminescence proposed several years ago by J.Schwinger. We shall first consider a model calculation based on Bogolubov coefficients relating the QED vacuum in the presence of an expanded bubble to that in the presence of a collapsed bubble. In this way we shall derive an estimate for the spectrum and total energy emitted. This latter will be shown to be proportional to the volume of space over which the refractive index changes, as Schwinger predicted. After this preliminary check we shall deal with the physical constraints that any viable dynamical model for SL has to satisfy in order to fit the experimental data. We shall emphasize the importance of the timescale of the change in refractive index. This discussion will led us to propose a somewhat different version of dynamical Casimir effect in which the change in volume of the bubble is no longer the only source for the change in the refractive index.