Class of colliding plane waves in terms of Jacobi functions
  We present a general class of noncolinear colliding wave solutions of the Einstein-Maxwell equations given in terms of fourth order polynomials, which in turn can be expressed through Jacobi functions depending on generalized advanced and retarded time coordinates. The solutions are characterized by six free parameters. The parameters can be chosen in such a way to avoid the generic focusing singularity 
Nora Breton (CINVESTAV--IPN), Alberto Garcia (CINVESTAV--IPN), Alfredo   Macias (UAM-Iztapalapa) and Gustavo Y\'a\~nez (CINV...