24 citations · 47 across the 15 of their papers we have counts for
15 papers
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…
EFT of Dark Energy with Cosmic Chronometers: Reconstructing Background EFT Functions
Fumiya Okamatsu, Kazufumi Takahashi
The effective field theory (EFT) of dark energy provides a model-independent framework for studying cosmology within scalar-tensor theories. In this work, we explore how the time e…
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…
Effective Field Theory of Perturbations on Arbitrary Black Hole Backgrounds with Spacelike Scalar Profile
Shinji Mukohyama, Emeric Seraille, Kazufumi Takahashi +1
We develop the effective field theory (EFT) of perturbations in the context of scalar-tensor theories with a spacelike scalar profile on arbitrary black hole backgrounds. Our const…
Resonance of black hole quasinormal modes in coupled systems
Takuya Takahashi, Hayato Motohashi, Kazufumi Takahashi
Black hole quasinormal modes (QNMs) can exhibit resonant excitations associated with avoided crossings in their complex frequency spectrum. Such resonance phenomena can serve as no…