2012/12/13 by Huan Yang, Fan Zhang, Aaron Zimmerman +3 · 7 citations
Physics and Astronomy · #Astrophysical Phenomena and Observations #Black Holes and Theoretical Physics #Condensed matter physics #Cosmology and Gravitation Theories #Eikonal equation #Gravitational wave #Mathematical physics #Merge (version control) #Physics #Quantum mechanics #Quasinormal mode #Spacetime #Spins #gr-qc #hep-th
paper · pdf · doi:10.1103/physrevd.87.041502
published as Phys. Rev. D 87, 041502(R) (2013) · 5 pages, 3 figures
arxiv created 2012/12/13 · openalex publication_date 2013/02/22 · arxiv updated 2013/03/05 · openalex created_date 2025/10/10 · openalex updated_date 2026/08/05
We show that nearly extremal Kerr black holes have two distinct sets of quasinormal modes, which we call zero-damping modes (ZDMs) and damped modes (DMs). The ZDMs exist for all harmonic indices l and m\ensuremath≥0, and their frequencies cluster onto the real axis in the extremal limit. The DMs have nonzero damping for all black hole spins; they exist for all counterrotating modes (m<0) and for corotating modes with 0\ensuremath≤\ensuremathμ\ensuremath\lesssim\ensuremathμc=0.74 (in the eikonal limit), where \ensuremathμ\ensuremath≡m/(l+1/2). When the two families coexist, ZDMs and DMs merge to form a single set of quasinormal modes as the black hole spin decreases. Using the effective potential for perturbations of the Kerr spacetime, we give intuitive explanations for the absence of DMs in certain areas of the spectrum and for the branching of the spectrum into ZDMs and DMs at large spins.