{
  "abstract": "We study the cosmology of self-interacting ultralight dark matter. The scalar field evolves from an early Hubble-frozen phase to a quartic-dominated radiation-like phase and finally to a quadratic matter-like phase. The intermediate phase increases the pre-recombination expansion rate and reduces the sound horizon, while the late phase allows the same field to contribute to dark matter. We implement the background and linear perturbations of a mixed cold-dark-matter and ultralight-dark-matter cosmology in CLASS. For $m=10^{-22}\\,{\\rm eV}$ and $\\tilde m\\simeq1\\,{\\rm eV}$, increasing the ultralight-dark-matter fraction raises the fixed-$θ_*$ value of $H_0$, lowers the late-time clustering amplitude, strengthens the scale-dependent matter-power suppression, and produces a smooth CMB-temperature residual reaching about $9\\%$ for the largest fraction considered. The model therefore generates simultaneous background and growth shifts in the directions relevant to the Hubble and structure-growth tensions. Establishing whether these shifts improve a joint fit requires a likelihood-level observational analysis.",
  "abstract_shown": true,
  "affiliations": [],
  "article_type": null,
  "arxiv": "2610.29582",
  "author_total": 2,
  "authors": [
    {
      "name": "Seokcheon Lee"
    },
    {
      "name": "Jae-Weon Lee"
    }
  ],
  "bibtex": "https://research.draconitic.com/paper/bmfe5z32858vs.bib",
  "cited_by": 0,
  "doi": "10.48550/arxiv.2610.29582",
  "fulltext_url": null,
  "id": "bmfe5z32858vs",
  "issns": [],
  "landing_url": "https://arxiv.org/abs/2610.29582",
  "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": "W7223199249",
  "pdf_url": "https://arxiv.org/pdf/2610.29582",
  "pmcid": null,
  "pmid": null,
  "published": "2026-10-21",
  "publisher": null,
  "ris": "https://research.draconitic.com/paper/bmfe5z32858vs.ris",
  "sources": [
    {
      "first_seen": "2026-10-30T12:34:19Z",
      "native_id": "2610.29582",
      "source": "arxiv",
      "url": "https://arxiv.org/abs/2610.29582"
    }
  ],
  "subjects": [
    {
      "field": "astronomy",
      "origin": "arxiv:astro-ph.CO",
      "subfield": "cosmology"
    }
  ],
  "title": "Cosmology of self-interacting ultralight dark matter: simultaneous shifts in the Hubble constant and structure growth",
  "title_text": "Cosmology of self-interacting ultralight dark matter: simultaneous shifts in the Hubble constant and structure growth",
  "type": "preprint",
  "updated_at": "2026-10-30T12:34:19Z",
  "url": "https://research.draconitic.com/paper/bmfe5z32858vs",
  "venue": "arXiv",
  "versions": []
}