12 papers
Excitation region of Kerr black hole quasinormal modes from Stokes geometry
Naritaka Oshita
We investigate the excitation region of black hole quasinormal modes (QNMs) from both analytical and numerical perspectives. On the analytical side, we propose that the QNM excitat…
Spectral instability of parametrized black hole quasinormal modes in the high-overtone limit via the exact WKB analysis
Taiga Miyachi, Ryo Namba, Hidetoshi Omiya +1
We study the asymptotic behavior of parametrized black hole quasinormal modes (QNMs) in the high-overtone limit. To gain insights into their analytical structure, we apply the exac…
Exceptional Lines and Excitation of (Nearly) Double-Pole Quasinormal Modes: A Semi-Analytic Study in the Nariai Black Hole
Nao Nakamoto, Naritaka Oshita
We show that quasinormal modes (QNMs) of a massive scalar field in Kerr-de Sitter and Myers-Perry black holes exhibit an exceptional line (EL), which is a continuous set of excepti…
Detectability of avoided crossings in black hole ringdowns
Hayato Imafuku, Naritaka Oshita, Hiroki Takeda
Quasinormal modes (QNMs) of black holes can exhibit avoided crossings (ACs), in which specific QNM frequencies approach each other while their amplitudes are enhanced and acquire n…
Dynamical Tidal Response of Non-rotating Black Holes: Connecting the MST Formalism and Worldline EFT
Hajime Kobayashi, Shinji Mukohyama, Naritaka Oshita +2
The response of a black hole (BH) to tidal forces encodes key information about the underlying gravitational theory and affects the waveform of gravitational waves emitted during b…
Quasinormal Modes from EFT of Black Hole Perturbations in Vector-Tensor Gravity
Shogo Tomizuka, Hajime Kobayashi, Naritaka Oshita +2
We study the dynamics of odd-parity perturbations on a static and spherically symmetric black hole background with a timelike vector field based on the effective field theory (EFT)…