{
  "abstract": "Gravitational-wave searches for subsolar-mass compact binaries have left a gap between the planetary-mass regime accessible to long-duration searches and the higher masses probed by conventional compact-binary analyses. We close this gap by searching for the inspiral of ultra-compact binaries with chirp masses $10^{-2}$--$10^{-1}\\,M_\\odot$ in LIGO O4ab data. Using the statistically robust BinaryGFH-v2 method, a time-frequency technique to search for rapidly evolving inspirals lasting minutes to hours, we cover this previously challenging parameter space with a computational cost of only $\\sim 350$ CPU-hours, and find no significant candidates. We thus set 90\\% confidence upper limits on the binary merger-rate density, providing the first gravitational-wave constraints across this chirp-mass range. Assuming that primordial-black-hole binaries formed in the early Universe with no binary suppression ($f_{\\rm sup}=1$), these results provide the first gravitational-wave constraints on the primordial-black-hole \\dmh fraction in this mass range, yielding upper limits with $f_{\\rm PBH}<1$ for equal-mass binaries with component masses $10^{-2}$--$10^{-1}\\,M_\\odot$ and asymmetric binaries with secondary masses $m_2=3\\times10^{-4}$--$10^{-2}\\,M_\\odot$ for a primary mass $m_1=2.5\\,M_\\odot$.",
  "abstract_shown": true,
  "affiliations": [],
  "article_type": null,
  "arxiv": "2609.16238",
  "author_total": 1,
  "authors": [
    {
      "name": "Andrew L. Miller"
    }
  ],
  "bibtex": "https://research.draconitic.com/paper/9xyvfzd32yhfb.bib",
  "cited_by": 0,
  "doi": "10.48550/arxiv.2609.16238",
  "fulltext_url": null,
  "id": "9xyvfzd32yhfb",
  "issns": [],
  "landing_url": "https://arxiv.org/abs/2609.16238",
  "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.IM"
    ],
    [
      "arxiv",
      "gr-qc"
    ],
    [
      "openalex",
      "3103|Pulsars and Gravitational Waves Research"
    ]
  ],
  "openalex": "W7213600328",
  "pdf_url": "https://arxiv.org/pdf/2609.16238",
  "pmcid": null,
  "pmid": null,
  "published": "2026-09-17",
  "publisher": null,
  "ris": "https://research.draconitic.com/paper/9xyvfzd32yhfb.ris",
  "sources": [
    {
      "first_seen": "2026-10-30T12:22:19Z",
      "native_id": "2609.16238",
      "source": "arxiv",
      "url": "https://arxiv.org/abs/2609.16238"
    }
  ],
  "subjects": [
    {
      "field": "astronomy",
      "origin": "arxiv:astro-ph.IM",
      "subfield": "instrumentation-methods"
    },
    {
      "field": "physics",
      "origin": "arxiv:gr-qc",
      "subfield": "gravitation"
    }
  ],
  "title": "Bridging the chirp-mass gap: searching for gravitational waves from inspiraling subsolar-mass ultra-compact binaries using LIGO O4ab data",
  "title_text": "Bridging the chirp-mass gap: searching for gravitational waves from inspiraling subsolar-mass ultra-compact binaries using LIGO O4ab data",
  "type": "preprint",
  "updated_at": "2026-10-30T12:22:19Z",
  "url": "https://research.draconitic.com/paper/9xyvfzd32yhfb",
  "venue": "arXiv",
  "versions": []
}