Self-consistent boundary-value problem for the adjoint Helmholtz equation

The self-consistent boundary-value problem of excitation is considered. In that problem the source function standing on the right side of Helmholtz equation is a solution of the homogeneous boundary value problem for this equation. It is shown that such a source along with our own wave (oscillation) creates an attached wave (oscillation). Since these waves (vibrations) exist only in the presence of a source of a designated type, it is proposed to classify them as connected to the supply.