A characteristic initial value problem in general relativity in the case of a perfect fluid with axial symmetry

An initial value problem for an axisymmetric perfect fluid in general relativity is considered by specifying data on an initial null hypersurface. The approach is an adaptation of the techniques introduced by Bondi, van der Burg & Metzner (1962) for dealing with asymptotically flat, empty space-time. A solution to the problem is shown to exist provided that the metric and physical variables are expanded in positive powers of a radial parameter and certain restrictive conditions at the origin are satisfied.

A method is described by means of which the characteristic initial value problem can be reduced to the Cauchy problem and examples are given of how it can be used in practice. As an application it is shown that the characteristic initial value problem for the Einstein equations in vacuum or with perfect fluid source is well posed when data are given on two transversely intersecting null hypersurfaces. A new discussion is given of the freely specifiable data for this problem.


This is the second of a sequence of papers on the numerical solution of the characteristic initial value problem in general relativity. Although the equations to be integrated have regular coefficients, the nonlinearity leads to the occurrence of singularities after a finite evolution time. In this paper we first discuss some novel techniques for integrating the equations right up to the singularities. The second half of the paper presents as examples the numerical evolution of the Schwarzschild and certain colliding plane wave space‒times.


This paper proves the existence of analytic solutions of the asymptotic characteristic initial value problem for Einstein’s field equations for analytic data on past null infinity and on an incoming null hypersurface.


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