{
  "abstract": "Peculiar velocities trace gravitational dynamics directly, complementing density-based clustering as wide-field spectroscopic surveys (DESI, Euclid, PFS) and kinetic Sunyaev-Zel'dovich (kSZ) measurements enter the precision era. Observational analyses of pairwise velocities and the pairwise kSZ signal remain largely restricted to linear and quasi-linear scales ($\\gtrsim20-30$ $h^{-1}Mpc$), despite substantial cosmological information available at smaller separations. We present a simulation-calibrated likelihood for $v_{12}(r,a)$, built on the exact pair conservation equation and PyCAMB HMcode-2020 non-linear clustering, and validate it against the QUIJOTE and TNG300-3 suites across resolution, particle sampling, box size, and redshift. Using QUIJOTE, we show that extending the fit to non-linear scales tightens the $1σ$ uncertainty on $Ω_\\mathrm{m}$ and $σ_8$ by $74\\%$ and $81\\%$ at $z=0.5$ ($r_{\\rm min}=4$ $h^{-1}Mpc$), and by $70\\%$ and $74\\%$ at $z=0$ ($r_{\\rm min}=8$ $h^{-1}Mpc$), relative to the linear-regime baseline ($r_{\\rm min}=50$ $h^{-1}Mpc$) (all at fixed $r_{max}=140$ $h^{-1}Mpc$); $σ(fσ_8)$ tightens by up to $86\\%$, and the joint $Ω_\\mathrm{m}$-$fσ_8$ Figure-of-Merit improves by up to $9.1\\times$ relative to the same baseline. These constraints are conditional on $h$ fixed at its QUIJOTE fiducial value, due to a near-degenerate response with $σ_8$; jointly sampling $h$ shifts and widens them substantially. This framework provides a validated route to exploiting that information in upcoming direct peculiar-velocity, redshift-space, and kSZ analyses.",
  "abstract_shown": true,
  "affiliations": [],
  "article_type": null,
  "arxiv": "2609.07976",
  "author_total": 4,
  "authors": [
    {
      "name": "Mariana Jaber"
    },
    {
      "name": "Antonela Taverna"
    },
    {
      "name": "Rasmus Strid"
    },
    {
      "name": "Wojciech A. Hellwing"
    }
  ],
  "bibtex": "https://research.draconitic.com/paper/46s0z8z5g19pc.bib",
  "cited_by": 0,
  "doi": "10.48550/arxiv.2609.07976",
  "fulltext_url": null,
  "id": "46s0z8z5g19pc",
  "issns": [],
  "landing_url": "https://arxiv.org/abs/2609.07976",
  "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": "W7212032108",
  "pdf_url": "https://arxiv.org/pdf/2609.07976",
  "pmcid": null,
  "pmid": null,
  "published": "2026-09-07",
  "publisher": null,
  "ris": "https://research.draconitic.com/paper/46s0z8z5g19pc.ris",
  "sources": [
    {
      "first_seen": "2026-10-30T12:19:49Z",
      "native_id": "2609.07976",
      "source": "arxiv",
      "url": "https://arxiv.org/abs/2609.07976"
    }
  ],
  "subjects": [
    {
      "field": "astronomy",
      "origin": "arxiv:astro-ph.CO",
      "subfield": "cosmology"
    }
  ],
  "title": "Non-linear Pairwise Velocities as a Cosmological Probe",
  "title_text": "Non-linear Pairwise Velocities as a Cosmological Probe",
  "type": "preprint",
  "updated_at": "2026-10-30T12:19:49Z",
  "url": "https://research.draconitic.com/paper/46s0z8z5g19pc",
  "venue": "arXiv",
  "versions": []
}