{
  "abstract": "Generating an appreciable abundance of primordial black holes (PBHs) requires a substantial enhancement of primordial curvature perturbations on small scales. In this Letter, we propose a new post-inflationary mechanism in which such an enhancement arises during a stiff, or kination, epoch. The mechanism is driven by metric vector perturbations sourced by the vector component of the electromagnetic stress-energy tensor associated with primordial magnetic fields (PMFs). Since these first-order vector modes remain approximately constant during kination, they act as persistent nonlinear sources for second-order scalar perturbations. We show that the resulting vector-induced curvature perturbations are amplified toward the infrared cutoff of the kination band and exhibit the characteristic scaling $\\mathcal P_{\\mathcal R}(k)\\propto k^{-5}$. As a concrete realization, we consider PMFs generated in a Ratra-type magnetogenesis scenario and find that the induced curvature perturbations can produce PBHs with an abundance large enough to constitute a substantial fraction of the dark matter.",
  "abstract_shown": true,
  "affiliations": [],
  "article_type": null,
  "arxiv": "2606.23307",
  "author_total": 4,
  "authors": [
    {
      "name": "Chang Han"
    },
    {
      "name": "Zu-Cheng Chen"
    },
    {
      "name": "Hongwei Yu"
    },
    {
      "name": "Puxun Wu"
    }
  ],
  "bibtex": "https://research.draconitic.com/paper/ct2pjxprkyjss.bib",
  "cited_by": 0,
  "doi": "10.48550/arxiv.2606.23307",
  "fulltext_url": null,
  "id": "ct2pjxprkyjss",
  "issns": [],
  "landing_url": "https://arxiv.org/abs/2606.23307",
  "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",
      "gr-qc"
    ]
  ],
  "openalex": null,
  "pdf_url": "https://arxiv.org/pdf/2606.23307",
  "pmcid": null,
  "pmid": null,
  "published": "2026-11-04",
  "publisher": null,
  "ris": "https://research.draconitic.com/paper/ct2pjxprkyjss.ris",
  "sources": [
    {
      "first_seen": "2026-11-05T15:20:55Z",
      "native_id": "2606.23307",
      "source": "arxiv",
      "url": "https://arxiv.org/abs/2606.23307"
    }
  ],
  "subjects": [
    {
      "field": "astronomy",
      "origin": "arxiv:astro-ph.CO",
      "subfield": "cosmology"
    },
    {
      "field": "physics",
      "origin": "arxiv:gr-qc",
      "subfield": "gravitation"
    }
  ],
  "title": "Primordial Black Holes from Vector-Induced Curvature Perturbations Sourced by Primordial Magnetic Fields",
  "title_text": "Primordial Black Holes from Vector-Induced Curvature Perturbations Sourced by Primordial Magnetic Fields",
  "type": "preprint",
  "updated_at": "2026-11-06T18:21:10Z",
  "url": "https://research.draconitic.com/paper/ct2pjxprkyjss",
  "venue": "arXiv",
  "versions": []
}