CYLINDRICAL-SPHERICAL EINSTEIN-MAXWELL SOLITONS

We present an analysis of a family of exact solutions of the Einstein- Maxwell equations, obtained using Alekseev's inverse scattering method . The solutions are simple soliton transformations of a Minkowski back ground and can be interpreted as cylindrical-spherical electrogravitat ional waves travelling on a flat background. Although the solutions ar e locally everywhere regular, the construction of a complete manifold (through appropriate extensions) requires a non-trivial topology, givi ng rise to the presence of ring-like structures connecting two differe nt asymptotically flat regions. The electrogravitational waves display the kind of phase shift previously described for cylindrical waves. A brief description of the construction procedure is also included.