Gravitational shock waves and vacuum fluctuations
arXiv:hep-th/9802072 · doi:10.1088/0264-9381/15/5/022
Abstract
We show that the vacuum expectation value of the stress-energy tensor of a scalar particle on the background of a spherical gravitational shock wave does not give a finite expression in second order perturbation theory, contrary to the case seen for the impulsive wave. No infrared divergences appear at this order. This result shows that there is a qualitative difference between the shock and impulsive wave solutions which is not exhibited in first order.
Submitted to Class. and Quant. Grav.,7 pages, no figures