89 citations · 774 across the 55 of their papers we have counts for
20 papers · 1 filter
Path to an exact WKB analysis of black hole quasinormal modes
Taiga Miyachi, Ryo Namba, Hidetoshi Omiya +1
We investigate black hole quasinormal modes using the exact WKB method. We perform an analytic continuation from the horizon to infinity along the positive real axis of the radial…
Remote Hawking-Moss instanton and the Lorentzian path integral
Daiki Saito, Naritaka Oshita
The Hawking-Moss (HM) bounce solution implies that the tunneling amplitude between vacua is uniquely determined by the vacuum energy at the initial vacuum and the top of a potentia…
Is the Coleman de Luccia action minimum?: AdS/CFT approach
Naritaka Oshita, Yutaro Shoji, Masahide Yamaguchi
We use the anti-de Sitter/conformal field theory (AdS/CFT) correspondence to find the least bounce action in an AdS false vacuum state, i.e., the most probable decay process of the…
From Entropy to Echoes: Counting the quasi-normal modes and the quantum limit of silence
Naritaka Oshita, Niayesh Afshordi
We estimate the canonical entropy of a quantum black hole by counting its quasi-normal modes. We first show that the partition function of a classical black hole, evaluated by coun…
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…
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…
Vacuum decay in the Lorentzian path integral
Takumi Hayashi, Kohei Kamada, Naritaka Oshita +1
We apply the Lorentzian path integral to the decay of a false vacuum and estimate the false-vacuum decay rate. To make the Lorentzian path integral convergent, the deformation of a…
Polychronic Tunneling: New Tunneling Processes Experiencing Euclidean and Lorentzian Evolution Simultaneously
Naritaka Oshita, Yutaro Shoji, Masahide Yamaguchi
We discuss new possible tunneling processes in the presence of gravity. We formulate quantum tunneling using the Wheeler-deWitt canonical quantization and the WKB approximation. Th…
Hawking-Moss transition with a black hole seed
Ruth Gregory, Ian G Moss, Naritaka Oshita +1
We extend the the concept of Hawking-Moss, or up-tunnelling, transitions in the early universe to include black hole seeds. The black hole greatly enhances the decay amplitude, how…
On catalyzed vacuum decay around a radiating black hole and the crisis of the electroweak vacuum
Takumi Hayashi, Kohei Kamada, Naritaka Oshita +1
False vacuum decay is a key feature in quantum field theories and exhibits a distinct signature in the early Universe cosmology. It has recently been suggested that the false vacuu…
Black Holes, Oscillating Instantons, and the Hawking-Moss transition
Ruth Gregory, Ian G. Moss, Naritaka Oshita
Static oscillating bounces in Schwarzschild de Sitter spacetime are investigated. The oscillating bounce with many oscillations gives a super-thick bubble wall, for which the total…
Small-mass naked singularities censored by the Higgs field
Naritaka Oshita
We investigate a vacuum decay around an over-spinning naked singularity by using the Israel junction condition. We found that if the Higgs field develops the second minimum at high…
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…
On Reflectivity of Quantum Black Hole Horizons
Naritaka Oshita, Qingwen Wang, Niayesh Afshordi
We study the reflectivity of quantum black hole (BH) horizons using detailed balance and fluctuation-dissipation theorem, finding a universal flux reflectivity given by the Boltzma…
Quantum radiation produced by the entanglement of quantum fields
Satoshi Iso, Naritaka Oshita, Rumi Tatsukawa +2
We investigate the quantum radiation produced by an Unruh-De Witt detector in a uniformly accelerating motion coupled to the vacuum fluctuations. Quantum radiation is nonvanishing,…
Resolution to the firewall paradox: The black hole information paradox and highly squeezed interior quantum fluctuations
Naritaka Oshita
Almheiri, Marolf, Polchinski, and Sully argued that, for a consistent black hole evaporation process, the horizon of a sufficiently old black hole should be replaced by a "firewall…
Unruh radiation produced by a uniformly accelerating charged particle in thermal random motions
Naritaka Oshita, Kazuhiro Yamamoto, Sen Zhang
In this study, we investigate the signature of the Unruh effect in quantum radiation from an accelerated charged particle interacting with vacuum fluctuations. Because a charged pa…
Entropic interpretation of the Hawking-Moss bounce
Naritaka Oshita, Jun'ichi Yokoyama
We revisit the derivation of the Hawking-Moss transition rate. Using the static coordinates, we show that the Euclidean action is entirely determined by the contribution of the ent…
Quantum radiation produced by a uniformly accelerating charged particle in thermal random motion
Naritaka Oshita, Kazuhiro Yamamoto, Sen Zhang
We investigate the properties of quantum radiation produced by a uniformly accelerating charged particle undergoing thermal random motions, which originates from the coupling to th…
Quantum radiation from a particle in an accelerated motion coupled to vacuum fluctuations
Naritaka Oshita, Kazuhiro Yamamoto, Sen Zhang
A particle in a uniformly accelerated motion exhibits Brownian random motions around the classical trajectory due to the coupling to the field vacuum fluctuations. Previous works s…