{
  "abstract": "We infer the Hubble constant $H_0$ from the ~400 Extragalactic Distance Database hosts with a tip of the red giant branch (TRGB) distance, calibrated on the geometric anchors of the Large Magellanic Cloud and NGC 4258. We forward-model the tip magnitudes and host redshifts including magnitude-limited selection, sky exposure, and density-dependent galaxy bias, conditioning on each of the 80 Manticore-Local realisations of the local density and peculiar-velocity fields in turn. As most hosts lie at $cz_{\\rm CMB} \\lesssim 1000$ km/s, where peculiar velocities are important, the inference is limited by the variance of these fields rather than by the TRGB calibration. For a fixed realisation, the redshift likelihood and density smoothing each move $H_0$ by less than 1 km/s/Mpc and a velocity monopole by $5.4 \\pm 3.4$ km/s/Mpc, whereas the field-to-field scatter in $H_0$ is 5.2 km/s/Mpc. Weighting the posteriors from each realisation equally gives $H_0 = 68.4 \\pm 5.9$ km/s/Mpc, while weighting each by its Bayesian evidence gives $72.3 \\pm 2.6$ km/s/Mpc. The latter value is set by a single particularly high-evidence realisation, making it sensitive to the finite sampling of the reconstruction posterior. This ladder therefore cannot yet arbitrate the Hubble tension. Extending the TRGB data beyond the present ~1000 km/s, together with improved reconstructions of the local Universe, would reduce the field-to-field scatter well below the 5.2 km/s/Mpc we find here.",
  "abstract_shown": true,
  "affiliations": [],
  "article_type": null,
  "arxiv": "2609.29996",
  "author_total": 3,
  "authors": [
    {
      "name": "Richard Stiskalek"
    },
    {
      "name": "Harry Desmond"
    },
    {
      "name": "Guilhem Lavaux"
    }
  ],
  "bibtex": "https://research.draconitic.com/paper/4ztyrtg2qcrcn.bib",
  "cited_by": 0,
  "doi": "10.48550/arxiv.2609.29996",
  "fulltext_url": null,
  "id": "4ztyrtg2qcrcn",
  "issns": [],
  "landing_url": "https://hal.science/hal-05830185v1",
  "language": "en",
  "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"
    ],
    [
      "arxiv",
      "astro-ph.GA"
    ],
    [
      "hal",
      "0.phys"
    ],
    [
      "hal",
      "1.phys.astr"
    ],
    [
      "openalex",
      "3103|Cosmology and Gravitation Theories"
    ]
  ],
  "openalex": "W7214358617",
  "pdf_url": "https://arxiv.org/pdf/2609.29996",
  "pmcid": null,
  "pmid": null,
  "published": "2026-09-24",
  "publisher": null,
  "ris": "https://research.draconitic.com/paper/4ztyrtg2qcrcn.ris",
  "sources": [
    {
      "first_seen": "2026-10-30T12:18:00Z",
      "native_id": "hal-05830185",
      "source": "hal",
      "url": "https://hal.science/hal-05830185v1"
    },
    {
      "first_seen": "2026-10-30T12:24:11Z",
      "native_id": "2609.29996",
      "source": "arxiv",
      "url": "https://arxiv.org/abs/2609.29996"
    }
  ],
  "subjects": [
    {
      "field": "astronomy",
      "origin": "arxiv:astro-ph.CO",
      "subfield": "cosmology"
    },
    {
      "field": "astronomy",
      "origin": "arxiv:astro-ph.GA",
      "subfield": "galaxies"
    },
    {
      "field": "physics",
      "origin": "hal:0.phys",
      "subfield": "general"
    }
  ],
  "title": "Two-rung ladder: $H_0$ from Tip of the Red Giant Branch and geometric anchors alone",
  "title_text": "Two-rung ladder: H_0 from Tip of the Red Giant Branch and geometric anchors alone",
  "type": "preprint",
  "updated_at": "2026-10-30T12:24:11Z",
  "url": "https://research.draconitic.com/paper/4ztyrtg2qcrcn",
  "venue": "HAL",
  "versions": []
}