Quantum scalar field propagator in a stochastic gravitational plane wave

A stochastic metric can appear in classical as well as in quantum gravity. We show that if the linearized stochastic Gaussian gravitational plane wave has the frequency spectrum $\omega^{4\gamma-1}$ ($0\leq \gamma<1$) then the equal-time propagator of the scalar field behaves as $p^{-\frac{1}{1-\gamma}}$for large momenta. We discuss models of quantum field theory where such anomalous behaviour can appear.