title: Measurement of stimulated Hawking emission in an analogue system.
abstract: Hawking argued that black holes emit thermal radiation via a quantum spontaneous emission. To address this issue experimentally, we utilize the analogy between the propagation of fields around black holes and surface waves on moving water. By placing a streamlined obstacle into an open channel flow we create a region of high velocity over the obstacle that can include surface wave horizons. Long waves propagating upstream towards this region are blocked and converted into short (deep-water) waves. This is the analogue of the stimulated emission by a white hole (the time inverse of a black hole), and our measurements of the amplitudes of the converted waves demonstrate the thermal nature of the conversion process for this system. Given the close relationship between stimulated and spontaneous emission, our findings attest to the generality of the Hawking process.
authors.affiliation: Department of Physics and Astronomy, University of British Columbia, Vancouver, Canada V6T 1Z1.
authors.forename: Silke
authors.initials: S
authors.lastname: Weinfurtner
authors.forename: Edmund W
authors.initials: EW
authors.lastname: Tedford
authors.forename: Matthew C J
authors.initials: MC
authors.lastname: Penrice
authors.forename: William G
authors.initials: WG
authors.lastname: Unruh
authors.forename: Gregory A
authors.initials: GA
authors.lastname: Lawrence