{
  "abstract": "The surface $r=\\infty$ of the Kerr-Bertotti-Robinson spacetime is not a genuine boundary. We construct its natural analytic extension and show that $r=+\\infty$ of one KBR region is smoothly connected to $r=-\\infty$ of a neighboring one. Repeated continuation produces an infinite chain of regions connected by wormhole-like bridges and exposes the neighboring ring singularity without an intervening horizon, which violates the weak cosmic censorship conjecture. We then study a test massless scalar field on a two-universe scattering segment to probe the stability of the spacetime. For axisymmetric perturbations, we analytically establish purely imaginary growing quasinormal modes for every $\\ell$ and trace their origin to the chronology-violating region. In the $(\\ell,m)=(2,2)$ sector, unstable branches occur for sufficiently large rotation and sufficiently small magnetic field. Their marginal real modes obey an exact horizon-flux balance, supporting a black-hole-bomb interpretation in which superradiant extraction is amplified by trapping within the double-barrier potential. The same cavity also supports families of weakly damped modes and may produce echo-like responses.",
  "abstract_shown": true,
  "affiliations": [],
  "article_type": null,
  "arxiv": "2609.07602",
  "author_total": 6,
  "authors": [
    {
      "name": "Yu-Sen Zhou"
    },
    {
      "name": "Liang-Bi Wu"
    },
    {
      "name": "Ming-Fei Ji"
    },
    {
      "name": "Wen-Tao Fu"
    },
    {
      "name": "Li-Ming Cao"
    },
    {
      "name": "Rong-Gen Cai"
    }
  ],
  "bibtex": "https://research.draconitic.com/paper/7smfdep0k9hwe.bib",
  "cited_by": 0,
  "doi": "10.48550/arxiv.2609.07602",
  "fulltext_url": null,
  "id": "7smfdep0k9hwe",
  "issns": [],
  "landing_url": "https://arxiv.org/abs/2609.07602",
  "language": null,
  "licence": "CC-BY-4.0",
  "licence_label": "CC BY 4.0",
  "licence_source": "article",
  "licence_url": "http://creativecommons.org/licenses/by/4.0/",
  "metadata_licence": "CC0-1.0",
  "native_subjects": [
    [
      "arxiv",
      "gr-qc"
    ],
    [
      "openalex",
      "3106|Black Holes and Theoretical Physics"
    ]
  ],
  "openalex": "W7212083474",
  "pdf_url": "https://arxiv.org/pdf/2609.07602",
  "pmcid": null,
  "pmid": null,
  "published": "2026-09-07",
  "publisher": null,
  "ris": "https://research.draconitic.com/paper/7smfdep0k9hwe.ris",
  "sources": [
    {
      "first_seen": "2026-10-30T12:19:48Z",
      "native_id": "2609.07602",
      "source": "arxiv",
      "url": "https://arxiv.org/abs/2609.07602"
    }
  ],
  "subjects": [
    {
      "field": "physics",
      "origin": "arxiv:gr-qc",
      "subfield": "gravitation"
    }
  ],
  "title": "Global structure and stability of Kerr-Bertotti-Robinson spacetime",
  "title_text": "Global structure and stability of Kerr-Bertotti-Robinson spacetime",
  "type": "preprint",
  "updated_at": "2026-10-30T12:19:48Z",
  "url": "https://research.draconitic.com/paper/7smfdep0k9hwe",
  "venue": "arXiv",
  "versions": []
}