COMBINING CAUCHY AND CHARACTERISTIC CODES .2. THE INTERFACE PROBLEM FOR VACUUM CYLINDRICAL SYMMETRY

This paper continues a series investigating methods of combining Cauch y and characteristic techniques in numerical relativity. We present a technique for passing gravitational wave information between an inner Cauchy region and an outer, compactified, characteristic region via a numerical interface. In this developmental work the method is applied to vacuum cylindrical spacetime with tare degrees of gravitational fre edom. A comparison of our numerical results with an analytic solution, and a number of numerical experiments involving the propagation of Ga ussian wave packets, indicate that the techniques presented here can p roduce very satisfactory results.