Ka. Milton et Yj. Ng, CASIMIR ENERGY FOR A SPHERICAL CAVITY IN A DIELECTRIC - APPLICATIONS TO SONOLUMINESCENCE, Physical review. E, Statistical physics, plasmas, fluids, and related interdisciplinary topics, 55(4), 1997, pp. 4207-4216
In a series of papers, Schwinger [Proc. Natl. Acad. Sci. U.S.A. 90, 95
8 (1993); 90, 2105 (1993); 90, 4505 (1993); 90, 7285 (1993); 91, 6473
(1994)] proposed that the ''dynamical Casimir effect'' might provide t
he driving force behind the puzzling phenomenon of sonoluminescence. M
otivated by that exciting suggestion, we have computed the static Casi
mir energy of a spherical cavity in an otherwise uniform material. As
expected, the result is divergent; yet a plausible finite answer is ex
tracted, in the leading uniform asymptotic approximation. This result
agrees with that found using zeta-function regularization. Numerically
, we find far too small an energy to account for the large burst of ph
otons seen in sonoluminescence. If the divergent result is retained, i
t is of the wrong sign to drive the effect. Dispersion does not resolv
e this contradiction. In the static approximation, the Fresnel drag te
rm is zero; on the other hand, the electrostriction could be comparabl
e to the Casimir term. It is argued that this adiabatic approximation
to the dynamical Casimir effect should be quite accurate.