{
  "abstract": "We formulate and numerically solve the nonlinear Teukolsky equations through third order, obtaining a first-principles calculation of cubic quasinormal-mode amplitudes for Kerr black holes. Our approach combines lower-order metric reconstruction in split light-cone gauges with a hyperboloidal, compactified formulation solved on complex radial contours. Spin-dependent complex coupling coefficients fix the cubic amplitudes from products of their linear parent amplitudes. We apply these predictions to a nonprecessing numerical-relativity waveform, including cubic products of the $(2,2)$ fundamental mode, its first overtone, and their conjugates. The predicted cubic terms improve agreement over selected early-ringdown fitting windows and shift inferred linear-overtone amplitudes without adding fitting parameters. $3M$ after the peak of $|h_{22}|$, the summed cubic contribution reaches approximately $38\\%$ of the total $h_{22}$ signal; $M$ is the initial total mass. These results identify an appreciable cubic response in early ringdown.",
  "abstract_shown": true,
  "affiliations": [],
  "article_type": null,
  "arxiv": "2610.20547",
  "author_total": 2,
  "authors": [
    {
      "name": "Neev Khera"
    },
    {
      "name": "Huan Yang"
    }
  ],
  "bibtex": "https://research.draconitic.com/paper/9g0h9jzjgwfvc.bib",
  "cited_by": 0,
  "doi": "10.48550/arxiv.2610.20547",
  "fulltext_url": null,
  "id": "9g0h9jzjgwfvc",
  "issns": [],
  "landing_url": "https://arxiv.org/abs/2610.20547",
  "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",
      "gr-qc"
    ],
    [
      "openalex",
      "3103|Pulsars and Gravitational Waves Research"
    ]
  ],
  "openalex": "W7222024467",
  "pdf_url": "https://arxiv.org/pdf/2610.20547",
  "pmcid": null,
  "pmid": null,
  "published": "2026-10-14",
  "publisher": null,
  "ris": "https://research.draconitic.com/paper/9g0h9jzjgwfvc.ris",
  "sources": [
    {
      "first_seen": "2026-10-30T12:29:31Z",
      "native_id": "2610.20547",
      "source": "arxiv",
      "url": "https://arxiv.org/abs/2610.20547"
    }
  ],
  "subjects": [
    {
      "field": "physics",
      "origin": "arxiv:gr-qc",
      "subfield": "gravitation"
    }
  ],
  "title": "Cubic Quasinormal Modes in the Black-Hole Ringdown",
  "title_text": "Cubic Quasinormal Modes in the Black-Hole Ringdown",
  "type": "preprint",
  "updated_at": "2026-10-30T12:29:31Z",
  "url": "https://research.draconitic.com/paper/9g0h9jzjgwfvc",
  "venue": "arXiv",
  "versions": []
}