Cooperative radiation and scattering of acoustic waves by gas bubbles in liquids

Cooperative effects involved with the radiation and scattering of sound by gas bubbles distributed in liquids is investigated analytically. Bubble interaction through the common friction radiation field is taken into account. It is shown that mutual interaction may lead to synchronization of the bubble oscillations and collective radiation. It is unlikely that a superradiance pulse will be observed. It is also shown that resonant bubble interaction causes considerable reduction of the scattering of sound, especially for harmonics.