Wave Propagation in Stochastic Spacetimes: Localization, Amplification and Particle Creation

Amplification and Particle Creation B. L. Hu and K. Shiokawa Department of Physics, University of Maryland, College Park, MD 20742, USA (umdpp 97-125, submitted to Phys. Rev. D on July 29, 1997) We study novel effects associated with electromagnetic wave propagation in a Robertson-Walker universe and the Schwarzschild spacetime with a small amount of metric stochasticity. We find that localization of electromagnetic waves occurs in a Robertson-Walker universe with time-independent metric stochasticity, while time-dependent metric stochasticity induces exponential instability in the particle production rate. For the Schwarzschild metric, timeindependent randomness can decrease the total luminosity of Hawking radiation due to multiple scattering of waves outside the black hole and gives rise to event horizon fluctuations and thus fluctuations in the Hawking temperature.