Transition radiation and the origin of sonoluminescence
It has been shown by Liberati et al. [Phys. Rev. D 61, 85023 (2000)] that a dielectric medium with a time-dependent refractive index may produce photons. We point out that a free electric charge that interacts with such a medium will emit quantum-mechanically modified transition radiation in which an arbitrary odd number of photons will be present. Excited atomic electrons will also exhibit a similarly modified emission spectrum. This effect may be directly observable in connection with sonoluminescence.
Jensen
B
Faculty of Science, Sogn and Fjordane College, N-6851 Sogndal, Norway.
Brevik
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