Gy. Qi et Bf. Schutz, ROBINSON-TRAUTMAN EQUATIONS AND CHANDRASEKHARS SPECIAL PERTURBATION OF THE SCHWARZSCHILD METRIC, General relativity and gravitation, 25(11), 1993, pp. 1185-1188
A perturbation wave solution of the Robinson-Trautman equations is pro
ved to be a perturbation of the Schwarzschild black hole which describ
es an outgoing axial gravitational wave and corresponds to a special c
ase of Chandrasekhar's algebraically special perturbation of the Schwa
rzschild metric.