The inverse scattering method for cylindrical gravitational waves
  The initial-value problem for cylindrical gravitational waves is studied through the development of the inverse scattering method scheme. The inverse scattering transform in this case can be viewed as a transformation of the Cauchy data to the data on the symmetry axis. Riemann-Hilbert problem, which serves as inverse transformation, is formulated in two different ways. We consider Einstein-Rosen waves to illustrate the method. 
G. G. Varzugin