43 citations · 156 across the 15 of their papers we have counts for
15 papers
Unified understanding of Alfvénic superradiance and the Blandford-Znajek process in a force-free black hole magnetosphere
Sousuke Noda, Masaaki Takahashi
We investigate the extraction of energy from a Kerr black hole via Alfvén waves (i.e., Alfvénic superradiance) in a force-free magnetosphere, in which the plasma inertia effects ar…
Weyl symmetry of the gradient-flow in information geometry
Tatsuaki Wada, Sousuke Noda
We have revisited the gradient-flow in information geometry from the perspective of Weyl symmetry. The gradient-flow equations are derived from the proposed action which is invaria…
One-dimensional linear analysis and numerical simulations of Alfven waves in a force-free magnetosphere around a Kerr black hole
Shinji Koide, Sousuke Noda, Masaaki Takahashi
We perform one-dimensional linear analysis and numerical simulations of the propagation of Alfven waves in a force-free magnetosphere along magnetic field lines around a spinning b…
Hamiltonian Formulation of Relativistic Magnetohydrodynamic Accretion on a General Spherically Symmetric and Static Black Hole: Quantum effects on Shock States
Mustapha Azreg-Aïnou, Mubasher Jamil, Sousuke Noda
In this paper, our aim is to extend our earlier work [A. K. Ahmed et al., Eur. Phys. J. C (2016) 76:280] thereby investigating an axisymmetric plasma flow with the angular momentum…
Spectroscopy of Kerr-AdS spacetime with the Heun function: Quasinormal modes, greybody factor, and evaporation
Sousuke Noda, Hayato Motohashi
We investigate quasinormal modes, greybody factor, and Hawking evaporation of a five-dimensional Kerr-anti de Sitter (AdS) black hole by solving a wave equation for a test mass…
Evaporation of Echoing Black Holes
Naritaka Oshita, Hayato Motohashi, Sousuke Noda
We compute the graybody factor and evaporation rate of a rotating black hole in the presence of a hypothetical reflective surface slightly outside the outer horizon radius, assumin…
Alfvénic superradiance for a monopole magnetosphere around a Kerr black hole
Sousuke Noda, Yasusada Nambu, Masaaki Takahashi +1
We explore superradiance for Alfvén waves (Alfvénic superradiance) in an axisymmetric rotating magnetosphere of a Kerr black hole within the force-free approximation. On the equato…
One-dimensional force-free numerical simulations of Alfven waves around a spinning black string
Shinji Koide, Sousuke Noda, Masaaki Takahashi +1
We performed one-dimensional force-free magnetodynamic numerical simulations of the propagation of Alfven waves along magnetic field lines around a spinning black-hole-like object,…
Interferometry of black holes with Hawking radiation
Yasusada Nambu, Sousuke Noda
We investigate the wave optical imaging of black holes with Hawking radiation. The spatial correlation function of Hawking radiation is expressed in terms of transmission and refle…
Exact solution for wave scattering from black holes: Formulation
Hayato Motohashi, Sousuke Noda
We establish an exact formulation for wave scattering of a massless field with spin and charge by a Kerr-Newman-de Sitter black hole. Our formulation is based on the exact solution…
Null Hypersurface Caustics, Closed Null Curves, and Super-Entropy
Sousuke Noda, Yen Chin Ong
Recently it was discovered that null hypersurfaces can develop caustics outside the event horizon of super-entropic Kerr-AdS black holes, in contrast to the usual Kerr-AdS case. In…
Blandford-Znajek process as Alfvénic superradiance
Sousuke Noda, Yasusada Nambu, Takuma Tsukamoto +1
The superradiant scattering of Alfvén waves (Alfvénic superradiance) in a forcefree magnetosphere is discussed to reveal the relationship between the Blandford-Znajek (BZ) process…
Wave Optics in Spacetimes with Compact Gravitating Object
Yasusada Nambu, Sousuke Noda, Yuichiro Sakai
We investigate the wave optics in spherically symmetric spacetimes: Schwarzschild black hole, spherical star with a perfect absorbing surface, and massless/massive Ellis wormholes.…
Analog rotating black holes in a magnetohydrodynamic inflow
Sousuke Noda, Yasusada Nambu, Masaaki Takahashi
We present a model of the analog geometry in a magnetohydrodynamic (MHD) flow. For the MHD flow with magnetic pressure-dominated and gas pressure-dominated conditions, we obtain th…
Wave Optics in Black Hole Spacetimes: Schwarzschild Case
Yasusada Nambu, Sousuke Noda
We investigate the wave optics in the Schwarzschild spacetime. Applying the standard formalism of wave scattering problems, the Green function represented by the sum over the parti…