CLASSICAL AND QUANTUM GRAVITY, vol.12, no.5, pp.1221-1227, 1995 (SCI-Expanded)
We show that quantum fluctuations, in particular vacuum polarization, vanish in the background of the spherical shock wave solution of the Einstein field equations recently found by Nutku. This work extends previous work on the similar problem, concluding that one can not change the null result previously obtained by using more general solutions.