204 citations · 1.6k across the 61 of their papers we have counts for
13 papers · 1 filter
Quantum teleportation in vacuum using only Unruh-DeWitt detectors
Jun-ichirou Koga, Gen Kimura, Kengo Maeda
We consider entanglement extraction into two two-level Unruh-DeWitt detectors from a vacuum of a neutral massless quantum scalar field in a four-dimensional spacetime, where the ge…
Inhomogeneous charged black hole solutions in asymptotically anti-de Sitter spacetime
Kengo Maeda, Takashi Okamura, Jun-ichirou Koga
We investigate static inhomogeneous charged planar black hole solutions of the Einstein-Maxwell system in an asymptotically anti-de Sitter spacetime. Within the framework of linear…
The final fate of instability of Reissner-Nordström-anti-de Sitter black holes by charged complex scalar fields
Kengo Maeda, Jun-ichirou Koga, Shunsuke Fujii
We investigate instability of 4-dimensional Reissner-Nordström-anti-de Sitter (RN-AdS) black holes with various topologies by charged scalar field perturbations. We numerically…
Update on Cosmic Censorship Violation in AdS
Thomas Hertog, Gary T. Horowitz, Kengo Maeda
We reexamine our proposed counterexample (gr-qc/0307102) to cosmic censorship in anti de Sitter (AdS) space, and find a gap in the construction. We mention some possible ways to cl…
Generic Cosmic Censorship Violation in anti de Sitter Space
Thomas Hertog, Gary T. Horowitz, Kengo Maeda
We consider (four dimensional) gravity coupled to a scalar field with potential V(ϕ). The potential satisfies the positive energy theorem for solutions that asymptotically tend to…
Asymptotic singular behavior of Gowdy spacetimes in string theory
Makoto Narita, Takashi Torii, Kengo Maeda
We study Gowdy spacetimes in the Einstein-Maxwell-dilaton-axion system and show by the Fuchsian algorithm that they have in general asymptotically velocity-term dominated s…
Violation of the cosmic no hair conjecture in Einstein-Maxwell-dilaton system
Kengo Maeda, Takashi Torii, Makoto Narita
The cosmic no hair conjecture is tested in the spherically symmetric Einstein-Maxwell-dilaton~(EMD) system with a positive cosmological constant . Firstly, we analytically show…
String excitation inside generic black holes
Kengo Maeda, Takashi Torii, Makoto Narita
We calculate how much a first-quantized string is excited after crossing the inner horizon of charged Vaidya solutions, as a simple model of generic black holes. To quantize a stri…
Do naked singularities generically occur in generalized theories of gravity?
Kengo Maeda, Takashi Torii, Makoto Narita
A new mechanism for causing naked singularities is found in an effective superstring theory. We investigate the gravitational collapse in a spherically symmetric Einstein-Maxwell-d…
Chronology Protection and Non-Naked Singularity
Kengo Maeda, Akihiro Ishibashi, Makoto Narita
We test the chronology protection conjecture in classical general relativity by investigating finitely vicious space-times. First we present singularity theorems in finitely viciou…
Upper bound for entropy in asymptotically de Sitter space-time
Kengo Maeda, Tatsuhiko Koike, Makoto Narita +1
We investigate nature of asymptotically de Sitter space-times containing a black hole. We show that if the matter fields satisfy the dominant energy condition and the cosmic censor…
Strong Cosmic Censorship and Causality Violation
Kengo Maeda, Akihiro Ishibashi
We investigate the instability of the Cauchy horizon caused by causality violation in the compact vacuum universe with the topology , which Moncr…
Causality violation and singularities
Kengo Maeda, Akihiro Ishibashi
We show that singularities necessarily occur when a boundary of causality violating set exists in a space-time under the physically suitable assumptions except the global causality…