{
  "abstract": "We present a minimal analytic framework to investigate the star formation efficiency per free-fall time, $ε_{\\rm ff}$, in giant molecular clouds (GMCs), focusing on the origin of the observed clustering around $ε_{\\rm ff} \\sim 0.01$. We model the time evolution of the turbulent velocity dispersion through a momentum balance between stellar feedback and turbulent dissipation, and show that this generically leads to a stable low-efficiency equilibrium with only weak dependence on global cloud properties. We extend the framework by including a phenomenological contribution from gravity-driven turbulence and find that both feedback- and gravity-driven motions converge to similar equilibrium states under typical GMC conditions. The efficiency can be expressed as the ratio between a gravitational velocity scale and an effective feedback velocity scale, providing a physically transparent interpretation of self-regulated star formation. The model provides a simple, physically motivated interpretation of observed gas-star formation scaling relations, including a Schmidt-like scaling at cloud scales and a Kennicutt-like scaling when averaged over cloud populations. Comparison with observed GMC properties shows agreement within a factor of a few and highlights the weak sensitivity of $ε_{\\rm ff}$ to cloud parameters. Despite its simplicity, the framework captures the leading-order interplay between turbulence, gravity, and feedback, and provides a physically transparent explanation for the origin and robustness of low star formation efficiencies in GMCs.",
  "abstract_shown": true,
  "affiliations": [],
  "article_type": "Journal reference: A&A, 712, A245 (2026)",
  "arxiv": "2607.06727",
  "author_total": 1,
  "authors": [
    {
      "name": "Erik Bertram"
    }
  ],
  "bibtex": "https://research.draconitic.com/paper/4a3dmnj6m7pzq.bib",
  "cited_by": 0,
  "doi": "10.48550/arxiv.2607.06727",
  "fulltext_url": null,
  "id": "4a3dmnj6m7pzq",
  "issns": [],
  "landing_url": "https://arxiv.org/abs/2607.06727",
  "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.GA"
    ],
    [
      "arxiv",
      "astro-ph.SR"
    ]
  ],
  "openalex": null,
  "pdf_url": "https://arxiv.org/pdf/2607.06727",
  "pmcid": null,
  "pmid": null,
  "published": "2026-07-07",
  "publisher": null,
  "ris": "https://research.draconitic.com/paper/4a3dmnj6m7pzq.ris",
  "sources": [
    {
      "first_seen": "2026-10-30T12:17:41Z",
      "native_id": "2607.06727",
      "source": "arxiv",
      "url": "https://arxiv.org/abs/2607.06727"
    }
  ],
  "subjects": [
    {
      "field": "astronomy",
      "origin": "arxiv:astro-ph.GA",
      "subfield": "galaxies"
    },
    {
      "field": "astronomy",
      "origin": "arxiv:astro-ph.SR",
      "subfield": "stellar"
    }
  ],
  "title": "A Momentum-Regulated Model For Star Formation Efficiency in Giant Molecular Clouds",
  "title_text": "A Momentum-Regulated Model For Star Formation Efficiency in Giant Molecular Clouds",
  "type": "preprint",
  "updated_at": "2026-10-30T12:17:41Z",
  "url": "https://research.draconitic.com/paper/4a3dmnj6m7pzq",
  "venue": "arXiv",
  "versions": [
    {
      "doi": "10.1051/0004-6361/202659688",
      "pid": null,
      "relation": "published-as",
      "title": null,
      "venue": null
    }
  ]
}