| Full text | |
| Author(s): |
Torres, Theo
;
Patrick, Sam
;
Coutant, Antonin
;
Richartz, Mauricio
;
Tedford, Edmund W.
;
Weinfurtner, Silke
Total Authors: 6
|
| Document type: | Journal article |
| Source: | Nature Physics; v. 13, n. 9, p. 833+, SEP 2017. |
| Web of Science Citations: | 46 |
| Abstract | |
When an incident wave scatters off of an obstacle, it is partially reflected and partially transmitted. In theory, if the obstacle is rotating, waves can be amplified in the process, extracting energy from the scatterer. Here we describe in detail the first laboratory detection of this phenomenon, known as superradiance(1-4). We observed that waves propagating on the surface of water can be amplified after being scattered by a draining vortex. The maximum amplification measured was 14% +/- 8%, obtained for 3.70 Hz waves, in a 6.25-cm-deep fluid, consistent with the superradiant scattering caused by rapid rotation. We expect our experimental findings to be relevant to black-hole physics, since shallow water waves scattering on a draining fluid constitute an analogue of a black hole(5-10), as well as to hydrodynamics, due to the close relation to over-reflection instabilities(11-13). (AU) | |
| FAPESP's process: | 15/14077-0 - Superradiance in dissipative systems |
| Grantee: | Maurício Richartz |
| Support Opportunities: | Scholarships abroad - Research |
| FAPESP's process: | 13/15748-0 - Analogue models: superradiance and stability |
| Grantee: | Maurício Richartz |
| Support Opportunities: | Scholarships abroad - Research |
| FAPESP's process: | 10/20123-1 - Analogue models of gravity |
| Grantee: | Maurício Richartz |
| Support Opportunities: | Scholarships in Brazil - Post-Doctoral |
| FAPESP's process: | 05/04219-0 - Limites da gravitacao semi classica: o regime transplanckiano. |
| Grantee: | Maurício Richartz |
| Support Opportunities: | Scholarships in Brazil - Doctorate (Direct) |
| FAPESP's process: | 13/09357-9 - Physics and Geometry of Spacetime |
| Grantee: | Alberto Vazquez Saa |
| Support Opportunities: | Research Projects - Thematic Grants |