Speaker
Yu-Sen Zhou
(University of Science and Technology of China)
Description
The surface $r=\infty$ in the Kerr--Bertotti--Robinson (KBR) spacetime is known not to be a physical boundary. We explicitly construct a natural extension across it, obtaining a wormhole that connects the exterior of one KBR black hole to the interior of a neighboring one. Depending on the parameters, the extended spacetime exhibits several distinct global causal structures and can contain a naked singularity. We further study a test scalar field and compute its quasinormal-mode spectrum, which suggests the presence of echoes naturally associated with the wormhole geometry. Unstable modes also emerge near extremality.
Authors
Yu-Sen Zhou
(University of Science and Technology of China)
Mr
Wen-Tao Fu
(University of Science and Technology of China)
Mr
Ming-Fei Ji
(University of Science and Technology of China)
Dr
Liang-Bi Wu
(Hangzhou Institute for Advanced Study, UCAS)
Prof.
Li-Ming Cao
(University of Science and Technology of China)