{
  "abstract": "Gravitational waves from massive black hole binaries detected by LISA will deliver luminosity distances without any astrophysical calibration, offering a probe of the expansion history independent of the cosmic distance ladder. Rather than asking how tightly LISA will constrain a single fiducial cosmology, we ask which of several mutually discrepant present-day cosmologies a future LISA dataset would render most self-consistent. We build mock catalogues of LISA bright sirens under three fiducial cosmologies drawn from datasets that participate in the current $H_0$ discrepancy (Planck 2018, Union3 and Pantheon+SH0ES), with a self-consistent error budget from instrumental noise, weak lensing and host peculiar velocities. We compare the posterior from the simulated LISA data alone with that of a real-data combination of Type Ia supernovae, DESI baryon acoustic oscillations, cosmic chronometers and the compressed Planck 2018 CMB, and quantify their internal tension in the $(H_0,Ω_m)$ plane, crossing each fiducial with three SN Ia compilations. The fiducial drives the tension, from $2.08σ$ to well beyond $5σ$, while the supernova compilation changes it by at most $1.2σ$. The discriminating power is strongly asymmetric: a Pantheon+SH0ES universe is inconsistent with every background we test, at a significance far in excess of $5σ$ and still at $3$-$5σ$ for the $10$-$20$ events expected from recent population models, whereas the Planck 2018 and Union3 fiducials, which differ by only $0.24$ km/s/Mpc in $H_0$, cannot be separated by any catalogue size. LISA bright sirens are therefore a sharp arbiter of the Cepheid-calibrated scenario and, on this error budget, silent between the other two.",
  "abstract_shown": true,
  "affiliations": [],
  "article_type": null,
  "arxiv": "2609.35317",
  "author_total": 3,
  "authors": [
    {
      "name": "M. F. A. Medeiros"
    },
    {
      "name": "F. C. Carvalho"
    },
    {
      "name": "L. L. Sales"
    }
  ],
  "bibtex": "https://research.draconitic.com/paper/cfzdb2xs4nedm.bib",
  "cited_by": 0,
  "doi": "10.48550/arxiv.2609.35317",
  "fulltext_url": null,
  "id": "cfzdb2xs4nedm",
  "issns": [],
  "landing_url": "https://arxiv.org/abs/2609.35317",
  "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",
      "astro-ph.CO"
    ],
    [
      "openalex",
      "3103|Cosmology and Gravitation Theories"
    ]
  ],
  "openalex": "W7214802979",
  "pdf_url": "https://arxiv.org/pdf/2609.35317",
  "pmcid": null,
  "pmid": null,
  "published": "2026-09-28",
  "publisher": null,
  "ris": "https://research.draconitic.com/paper/cfzdb2xs4nedm.ris",
  "sources": [
    {
      "first_seen": "2026-10-30T12:25:12Z",
      "native_id": "2609.35317",
      "source": "arxiv",
      "url": "https://arxiv.org/abs/2609.35317"
    }
  ],
  "subjects": [
    {
      "field": "astronomy",
      "origin": "arxiv:astro-ph.CO",
      "subfield": "cosmology"
    }
  ],
  "title": "LISA bright sirens as a tiebreaker among cosmologies in tension",
  "title_text": "LISA bright sirens as a tiebreaker among cosmologies in tension",
  "type": "preprint",
  "updated_at": "2026-10-30T12:25:12Z",
  "url": "https://research.draconitic.com/paper/cfzdb2xs4nedm",
  "venue": "arXiv",
  "versions": []
}