Black hole lasers

摘要: High frequency dispersion does not alter the low spectrum of Hawking radiation from a single black hole horizon, whether entails subluminal or superluminal group velocities. We show here that in presence an inner horizon as well outer case differs dramatically however. The negative energy partners quanta return to and stimulate more if field is bosonic suppress it fermionic. This process leads exponential growth damping radiated flux correlations among emitted at different times, unlike usual effect. These phenomena may be observable condensed matter analogues exhibit ``superluminal'' dispersion.