Asymptotic Calculation of the Intensity of Dipole Electromagnetic Radiation of an Uncharged Drop Oscillating in the Electrostatic Field

An analysis is carried out on the electromagnetic radiation of an uncharged drop oscillating in an electrostatic field using nonlinear asymptotic calculations for two small parameters (the value of a dimensionless stationary deformation of an initially spherical drop and the amplitude of its capillary oscillations). In the external electrostatic field, on the top of the drop, electric charges with the opposite signs are formed, to which the "effective" charges located on the drop's symmetry axis are added relatively. Since the distance between those "effective" charges is about the length of the drop's radius, they form a dipole, which at the distances much longer than the sizes of the drop creates a similar electric field as the drop itself. During the oscillation of the drop surface, the dipole will also oscillate, which will generate the electromagnetic waves of the dipole type.