On Quantization of Surface Perturbations of Ideal Fluid in Uniform External Electric Field

The small surface perturbations of dielectric ideal fluid in the gap between two planar electrodes are considered. It is shown that the system's linearized Hamiltonian per unit length can be presented as a sum of Hamiltonians of harmonic oscillators. It is found that the electric field influence results in appearance of the selective scale of perturbations and the surface instability in the electric field may be interpreted as bose-condensation of quanta of surface excitations (electroripplons).