46 citations · 138 across the 13 of their papers we have counts for
14 papers
Floquet Instability of Photon-Axion Conversion
Yuuki Sugiyama, Kazushige Ueda
The discovery of axions would provide evidence for physics beyond the Standard Model. In this work, we investigate axion-photon conversion in the presence of a background magnetic…
Imprints of Dark Photons on Gravitational Wave Polarizations
Kimihiro Nomura, Jiro Soda, Kazushige Ueda +1
We study conversion processes between gravitons and dark photons and reveal the effects of dark photons on the polarization of gravitational waves. Considering cosmological dark ma…
Big-Bang Nucleosynthesis on a bubble universe nucleated in Kerr-AdS Black Hole
Akira Dohi, Issei Koga, Kazushige Ueda
We present the Big-Bang Nucleosynthesis (BBN) simulation with a bubble universe scenario around a rotating black hole (BH) in Kerr-AdS spacetime to explain recently updated obs…
A peak in the power spectrum of primordial gravitational waves induced by primordial dark magnetic fields
Sugumi Kanno, Ann Mukuno, Jiro Soda +1
Dark gauge fields have been discussed as candidates for dark matter recently. If they existed, primordial dark magnetic fields during inflation would have existed. It is believed t…
Impact of quantum entanglement induced by magnetic fields on primordial gravitational waves
Sugumi Kanno, Ann Mukuno, Jiro Soda +1
There exist observational evidence to believe the existence of primordial magnetic fields generated during inflation. We study primordial gravitational waves (PGWs) during inflatio…
Anisotropic warm inflation
Sugumi Kanno, Ann Mukuno, Jiro Soda +1
Anisotropic inflation is a model succeeded in explaining statistical anisotropy. Warm inflation is a model succeeded in providing a mechanism of reheating during inflation. We stud…
dS universe emergent from Kerr-AdS spacetime: bubble nucleation catalyzed by a black hole
Issei Koga, Naritaka Oshita, Kazushige Ueda
The emergence of a four-dimensional de Sitter (dS) universe on an expanding bubble in the five-dimensional anti-de Sitter (AdS) background has been suggested as a possi…
Conversion of squeezed gravitons into photons during inflation
Sugumi Kanno, Jiro Soda, Kazushige Ueda
It is believed that relic gravitons are squeezed during inflation. If so, quantum noise induced by them can be significantly enhanced in current interferometers. However, decoheren…
Global study of the scalar quasi-normal modes of Kerr-AdS black holes: Stability, thermality, and horizon area quantization
Issei Koga, Naritaka Oshita, Kazushige Ueda
We numerically explore the structure of quasi-normal (QN) frequencies of the five-dimensional small and large Kerr-anti de Sitter (Kerr-AdS) black hole with equal and unequal…
Entanglement of the Vacuum between Left, Right, Future, and Past: Dirac spinor in Rindler spaces and Kasner spaces
Kazushige Ueda, Atsushi Higuchi, Kazuhiro Yamamoto +2
We study the relations of the positive frequency mode functions of Dirac field in 4-dimensional Minkowski spacetime covered with Rindler and Kasner coordinates, and describe the ex…
Relativistic quantum bouncing particles in a homogeneous gravitational field
Ar Rohim, Kazushige Ueda, Kazuhiro Yamamoto +1
In this paper, we study the relativistic effect on the wave functions for a bouncing particle in a gravitational field. Motivated by the equivalence principle, we investigate the K…
Vacuum decays around spinning black holes
Naritaka Oshita, Kazushige Ueda, Masahide Yamaguchi
We investigate a vacuum decay around a spinning seed black hole by using the Israel junction condition and conclude that the spin of black hole would suppress a vacuum decay rate c…
Entanglement of the Vacuum between Left, Right, Future, and Past: The Origin of Entanglement-Induced Quantum Radiation
Atsushi Higuchi, Satoshi Iso, Kazushige Ueda +1
The Minkowski vacuum state is expressed as an entangled state between the left and right Rindler wedges when it is constructed on the Rindler vacuum. In this paper, we further exam…
Entanglement-induced quantum radiation
Satoshi Iso, Rumi Tatsukawa, Kazushige Ueda +1
Quantum entanglement of the Minkowski vacuum state between left and right Rindler wedges generates thermal behavior in the right Rindler wedge, which is known as the Unruh effect.…