{
  "abstract": "We simulate the gravitational lensing of gravitational waves (GWs) by a Kerr black hole using a $(1+1)$-dimensional time-domain mode-sum approach. To enable efficient explicit time evolution, we implement a localized hyperboloidal foliation combined with a static field redefinition, ensuring bounded characteristic speeds across an extended, uniform tortoise-coordinate grid. Incident GW initial data are constructed by projecting a plane-wave Weyl tensor onto the Kinnersley tetrad. Through local spin-dyad rotations and Wigner $D$-matrix transformations, our framework accommodates both idealized wave packets and realistic binary coalescence signals at arbitrary incidence and polarization angles. To accurately resolve the lensed waveforms, we evolve over $68,000$ coupled $(j,m)$ modes. Our results reveal that a Kerr black hole acts as a diffraction-limited thick lens, focusing GWs into a forward beam. For idealized wave packets, the primary prompt pulse exhibits a spin-independent transverse Gaussian profile, whereas the subsequent lensing coda is sensitive to the black hole's spin. For binary coalescence signals, strong-field lensing substantially modifies the post-merger ringdown. However, the lensed inspiral and merger phases in Kerr and Schwarzschild backgrounds are virtually identical, yielding waveform mismatches below $2.2\\times10^{-5}$ across various inclinations and polarizations. These findings demonstrate that non-spinning Schwarzschild models provide an accurate and computationally economical surrogate to search for strong-field lensing signatures with current ground-based detectors.",
  "abstract_shown": true,
  "affiliations": [],
  "article_type": null,
  "arxiv": "2610.39181",
  "author_total": 1,
  "authors": [
    {
      "name": "Jian-hua He"
    }
  ],
  "bibtex": "https://research.draconitic.com/paper/1fbbgkpnz0006.bib",
  "cited_by": 0,
  "doi": "10.48550/arxiv.2610.39181",
  "fulltext_url": null,
  "id": "1fbbgkpnz0006",
  "issns": [],
  "landing_url": "https://arxiv.org/abs/2610.39181",
  "language": null,
  "licence": "LicenseRef-arXiv-nonexclusive-1.0",
  "licence_label": "arXiv licence",
  "licence_source": "article",
  "licence_url": "http://arxiv.org/licenses/nonexclusive-distrib/1.0/",
  "metadata_licence": "CC0-1.0",
  "native_subjects": [
    [
      "arxiv",
      "astro-ph.HE"
    ],
    [
      "arxiv",
      "gr-qc"
    ]
  ],
  "openalex": null,
  "pdf_url": "https://arxiv.org/pdf/2610.39181",
  "pmcid": null,
  "pmid": null,
  "published": "2026-10-29",
  "publisher": null,
  "ris": "https://research.draconitic.com/paper/1fbbgkpnz0006.ris",
  "sources": [
    {
      "first_seen": "2026-10-30T12:36:23Z",
      "native_id": "2610.39181",
      "source": "arxiv",
      "url": "https://arxiv.org/abs/2610.39181"
    }
  ],
  "subjects": [
    {
      "field": "astronomy",
      "origin": "arxiv:astro-ph.HE",
      "subfield": "high-energy-astrophysics"
    },
    {
      "field": "physics",
      "origin": "arxiv:gr-qc",
      "subfield": "gravitation"
    }
  ],
  "title": "Gravitational lensing of gravitational waves by a Kerr black hole",
  "title_text": "Gravitational lensing of gravitational waves by a Kerr black hole",
  "type": "preprint",
  "updated_at": "2026-11-01T12:20:45Z",
  "url": "https://research.draconitic.com/paper/1fbbgkpnz0006",
  "venue": "arXiv",
  "versions": []
}