Diffraction by a rigid,mobile inclusion

The long-wavelength problem of scattering by a rigid inclusion in an elastic medium is studied. Taking into account the mobility of the inclusion leads to non-classical boundary conditions. At infinity the solution is sought in the form of a multipole ansatz. Near the scatterer a series of static problems is obtained. In the course of the solution the integral characteristic of the rigid mobile inclusion, whose scalar analog is the tensor e_ij studied by Polya and Szegö, arises in a natural manner.Translated from Zapiski Nauchnykh Seminarov Leningradskogo Otdeleniya Matematicheskogo Instituta im. V. A. Steklova AN SSSR, Vol. 156, pp. 61–68, 1986.