Superradiant instabilities in astrophysical systems

Helvi Witek,* Vitor Cardoso, Akihiro Ishibashi, and Ulrich Sperhake Departamento de Fı́sica, CENTRA, Instituto Superior Técnico, Universidade Técnica de Lisboa—UTL, Avenida Rovisco Pais 1, 1049 Lisboa, Portugal Department of Applied Mathematics and Theoretical Physics, Centre for Mathematical Sciences, University of Cambridge, Wilberforce Road, Cambridge CB3 0WA, United Kingdom Department of Physics and Astronomy, The University of Mississippi, University, Mississippi 38677, USA Department of Physics, Kinki University, Higashi-Osaka 577-8502, Japan Institute of Space Sciences, CSIC-IEEC, 08193 Bellaterra, Spain California Institute of Technology, Pasadena, California 91125, USA (Received 10 December 2012; published 5 February 2013)