Detecting rotational superradiance in fluid laboratories

Cardoso, Vitor; Coutant, Antonin; Richartz, Mauricio; Weinfurtner, Silke

Abstract

Rotational superradiance was predicted theoretically decades ago, and is chiefly responsible for a number of important effects and phenomenology in black-hole physics. However, rotational superradiance has never been observed experimentally. Here, with the aim of probing superradiance in the lab, we investigate the behavior of sound and surface waves in fluids resting in a circular basin at the center of which a rotating cylinder is placed. We show that with a suitable choice for the material of the cylinder, surface and sound waves are amplified. Two types of instabilities are studied: one sets in whenever superradiant modes are confined near the rotating cylinder and the other, which does not rely on confinement, corresponds to a local excitation of the cylinder. Our findings are experimentally testable in existing fluid laboratories and, hence, offer experimental exploration and comparison of dynamical instabilities arising from rapidly rotating boundary layers in astrophysical as well as in fluid dynamical systems.

Citation

Cardoso, V., Coutant, A., Richartz, M., & Weinfurtner, S. (2016). Detecting rotational superradiance in fluid laboratories. Physical Review Letters, 117(27), Article 271101. https://doi.org/10.1103/PhysRevLett.117.271101

• Journal Article Type: Article
• Acceptance Date: Nov 30, 2016
• Publication Date: Dec 29, 2016
• Deposit Date: Feb 27, 2017
• Publicly Available Date: Feb 27, 2017
• Journal: Physical Review Letters
• Print ISSN: 0031-9007
• Electronic ISSN: 1079-7114
• Publisher: American Physical Society
• Peer Reviewed: Peer Reviewed
• Volume: 117
• Issue: 27
• Article Number: 271101
• DOI: https://doi.org/10.1103/PhysRevLett.117.271101
• Public URL: https://nottingham-repository.worktribe.com/output/831829
• Publisher URL: http://journals.aps.org/prl/abstract/10.1103/PhysRevLett.117.271101
• Contract Date: Feb 27, 2017