4 papers
Quasinormal modes, complex null geodesics and singularity resolution in regular AdS black holes
Heng-Yu Chen, Yasuaki Hikida, Yasutaka Koga
The black hole singularity is hidden behind its horizon, and it is difficult to determine whether it is resolved by quantum gravity or stringy effects. For an AdS-Schwarzschild bla…
Realization of de Sitter spacetime in AdS/CFT
Yasutaka Koga, Keiju Murata, Seiji Terashima
We construct horizonless, everywhere-regular solitons containing a de~Sitter core inside an asymptotically anti--de~Sitter spacetime, using an ordinary action of Einstein gravity,…
Bulk-cone singularities and echoes from AdS exotic compact objects
Heng-Yu Chen, Yasuaki Hikida, Yasutaka Koga
The region near a black hole horizon may be modified by quantum gravity effects that resolve the singularity. Such geometry may be represented by an exotic compact object. Because…
AdS gravastar and its signatures from dual conformal field theory
Heng-Yu Chen, Yasuaki Hikida, Yasutaka Koga
Quantum gravity effects are expected to resolve the black hole singularity and the effects may deform the region near but outside the horizon. Applying AdS/CFT correspondence, we s…