{
  "abstract": "Pauli exclusion is often regarded as imposing a model-independent lower bound on the mass of fermionic dark matter in galaxies. We show that dark-sector interactions can substantially weaken this conclusion. In particular, eV-scale fermions can form bound structures with the characteristic sizes and densities of dwarf galaxies, thereby circumventing the conventional Tremaine-Gunn mass constraint. Within these objects, the degeneracy pressure is balanced by an attractive finite-range scalar Yukawa force that is significantly stronger than gravity. The interaction acts on dwarf-galaxy scales while remaining screened on larger scales. We derive the evolution of the resulting dark-matter fluid and identify a viable cosmological history in which structures first form gravitationally, with the new interaction becoming active only at late times. As a proof of concept, we construct a model in which a single late-time phase transition generates the required dynamics. These results provide a new route to exceptionally light fermionic dark matter and demonstrate that dark-sector interactions can qualitatively alter conventional phase-space limits.",
  "abstract_shown": true,
  "affiliations": [],
  "article_type": null,
  "arxiv": "2609.01727",
  "author_total": 4,
  "authors": [
    {
      "name": "Joel Barir"
    },
    {
      "name": "Diego Blas"
    },
    {
      "name": "Anubhav Mathur"
    },
    {
      "name": "Tomer Volansky"
    }
  ],
  "bibtex": "https://research.draconitic.com/paper/a2ryv3zysw200.bib",
  "cited_by": 0,
  "doi": "10.48550/arxiv.2609.01727",
  "fulltext_url": null,
  "id": "a2ryv3zysw200",
  "issns": [],
  "landing_url": "https://arxiv.org/abs/2609.01727",
  "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"
    ],
    [
      "arxiv",
      "hep-ph"
    ],
    [
      "openalex",
      "3106|Dark Matter and Cosmic Phenomena"
    ]
  ],
  "openalex": "W7207518459",
  "pdf_url": "https://arxiv.org/pdf/2609.01727",
  "pmcid": null,
  "pmid": null,
  "published": "2026-09-01",
  "publisher": null,
  "ris": "https://research.draconitic.com/paper/a2ryv3zysw200.ris",
  "sources": [
    {
      "first_seen": "2026-10-30T12:18:16Z",
      "native_id": "2609.01727",
      "source": "arxiv",
      "url": "https://arxiv.org/abs/2609.01727"
    }
  ],
  "subjects": [
    {
      "field": "astronomy",
      "origin": "arxiv:astro-ph.CO",
      "subfield": "cosmology"
    },
    {
      "field": "physics",
      "origin": "arxiv:hep-ph",
      "subfield": "high-energy"
    }
  ],
  "title": "Tremaine-Gunn Control: Evading Bounds on Light Fermion Dark Matter",
  "title_text": "Tremaine-Gunn Control: Evading Bounds on Light Fermion Dark Matter",
  "type": "preprint",
  "updated_at": "2026-10-30T12:18:16Z",
  "url": "https://research.draconitic.com/paper/a2ryv3zysw200",
  "venue": "arXiv",
  "versions": []
}