  A matrix formulation is derived for the calculation of the swimming speed and
the power required for swimming of an assembly of rigid spheres immersed in a
viscous fluid of infinite extent. The spheres may have arbitrary radii and may
interact with elastic forces. The analysis is based on the Stokes mobility
matrix of the set of spheres, defined in low Reynolds number hydrodynamics. For
small amplitude swimming optimization of the swimming speed at given power
leads to an eigenvalue problem. The method allows straightforward calculation
of the swimming performance of structures modeled as assemblies of interacting
rigid spheres.
