28 citations · 43 across the 7 of their papers we have counts for
9 papers
Black Hole Quasinormal Mode Resonances and Reconnections in Coupled Systems
Leah Jenks, Hayato Motohashi, Kazufumi Takahashi +2
Black hole quasinormal modes (QNMs) provide a window into the underlying structure of black holes and the environments in which they arise. QNMs have particularly rich dynamics in…
Avoided crossings and resonances in black hole ringdown with coupled fields: A case study of the Einstein-Maxwell-axion system
Takuya Takahashi, Hayato Motohashi, Kazufumi Takahashi
Avoided crossings in black hole quasinormal-mode (QNM) spectra exhibit characteristic resonant properties, including enhanced excitation factors. We extend the study of this phenom…
Constant-Roll Inflation: Analytical Formulae for Power Spectrum and Implications for Induced Gravitational Waves
Hayato Motohashi, Shi Pi, Yuichiro Tada +1
Constant-roll inflation provides a simple and analytically tractable framework for describing transient departures from slow roll, including non-attractor phases that can enhance t…
Ringdown analysis of GW250114 with orthonormal modes
Motoki Suzuki, Kei-ichiro Kubota, Soichiro Morisaki +2
GW250114 is the loudest gravitational wave event to date observed by LIGO-Virgo-KAGRA Collaboration. Owing to its high signal-to-noise ratio (SNR), previous analyses based on quasi…
Scalar quasinormal modes of rotating black holes in parity-violating gravity
Hiroaki W. H. Tahara, Hayato Motohashi, Kazufumi Takahashi +1
Recently, an exact rotating black hole solution in a parity-violating theory of gravity was obtained via a conformal transformation of the Kerr solution in general relativity, with…
Probing higher curvature gravity via ringdown with overtones
Keisuke Nakashi, Masashi Kimura, Hayato Motohashi +1
We investigate metric perturbations of a spherically symmetric black hole in higher curvature gravity. We show that higher curvature corrections deform the near-horizon region of t…
Black hole spectroscopy: from theory to experiment
Emanuele Berti, Vitor Cardoso, Gregorio Carullo +65
The "ringdown" radiation emitted by oscillating black holes has great scientific potential. By carefully predicting the frequencies and amplitudes of black hole quasinormal modes a…
Primordial black holes and induced gravitational waves from logarithmic non-Gaussianity
Ryoto Inui, Cristian Joana, Hayato Motohashi +3
We investigate the formation of primordial black hole (PBH) based on numerical relativity simulations and peak theory as well as the corresponding scalar induced gravitational wave…
Constant roll and non-Gaussian tail in light of logarithmic duality
Ryoto Inui, Hayato Motohashi, Shi Pi +2
The curvature perturbation in a model of constant-roll (CR) inflation is interpreted in view of the logarithmic duality discovered in Ref. [1] according to the formalism. We c…