Collision of shock waves in Einstein-Maxwell theory with a cosmological constant: A special solution

Postcollision space-times of the Cartesian product form M^'×M^'', where M^' and M^'' are two-dimensional manifolds, are known with M^' and M^'' having constant curvatures of equal and opposite sign (for the collision of electromagnetic shock waves) or of the same sign (for the collision of gravitational shock waves). We construct here a new explicit postcollision solution of the Einstein-Maxwell vacuum field equations with a cosmological constant for which M^' has constant (nonzero) curvature and M^'' has zero curvature.