Electrical properties of a Bose-condensate

It is shown that the condensate of a degenerated Bose-gas has electric properties which are revealed in the condensate dynamics and are not limited by the trivial atomic polarization in an applied field. Small oscillations in a Bose-gas are considered, and corrections to the Bogolyubov spectrum of elementary excitations are found. For a degenerate Bose-gas, the corrections are proportional to (k a)4, where k is the wavevector and a is the atomic radius