{
  "abstract": "We study single-field slow-roll inflation in metric-affine gravity (MAG). We consider the most general action up to operators linear in curvature and quadratic in the distortion, without propagating torsion and non-metricity. We first impose projective invariance and promote every coefficient to a function of the scalar field. After integrating out the non-dynamical distortion, the net contribution is a correction $k(ϕ)$ to the scalar kinetic term. We then consider the class of $ξ$-attractors for which the non-minimal couplings and the scalar potential are fixed by a single function $f(ϕ)$. It is well-known that in the metric formulation the strong-coupling regime is universally the Starobinsky attractor. In the Palatini framework, instead, this attractor is lost and the predictions become model-dependent. Here, we show that the MAG framework restores universality: in the strong coupling limit with finite ratios of the distortion couplings to $ξ$ we have an $α$-attractor, $n_s=1-2/N_*$ and $r=12α/N_*^2$, with $α=1+ζ/(6ξ)$. The ratio $ζ/ξ$ encodes the distortion contribution. Starobinsky and Palatini inflation are recovered as specific limits. Through a numerical parameter scan we show that almost all the healthy points lie on one of the two attractors : either Nieh-Yan-like inflation (studied in a previous work and extended here) or the new MAG $α$-attractor found here. Finally, we explicitly drop projective invariance and analyse the general MAG theory. The same large-field asymptotic structure survives. We conclude that no extra inflationary phenomenology is reached by the non-projectively invariant operators: the $α$-attractor is a general prediction of MAG.",
  "abstract_shown": true,
  "affiliations": [],
  "article_type": null,
  "arxiv": "2611.06750",
  "author_total": 2,
  "authors": [
    {
      "name": "Ilaria Andrei"
    },
    {
      "name": "Christian Dioguardi"
    }
  ],
  "bibtex": "https://research.draconitic.com/paper/0t4hqwk3824ys.bib",
  "cited_by": 0,
  "doi": "10.48550/arxiv.2611.06750",
  "fulltext_url": null,
  "id": "0t4hqwk3824ys",
  "issns": [],
  "landing_url": "https://arxiv.org/abs/2611.06750",
  "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"
    ],
    [
      "arxiv",
      "hep-ph"
    ]
  ],
  "openalex": null,
  "pdf_url": "https://arxiv.org/pdf/2611.06750",
  "pmcid": null,
  "pmid": null,
  "published": "2026-11-04",
  "publisher": null,
  "ris": "https://research.draconitic.com/paper/0t4hqwk3824ys.ris",
  "sources": [
    {
      "first_seen": "2026-11-05T15:20:56Z",
      "native_id": "2611.06750",
      "source": "arxiv",
      "url": "https://arxiv.org/abs/2611.06750"
    }
  ],
  "subjects": [
    {
      "field": "astronomy",
      "origin": "arxiv:astro-ph.CO",
      "subfield": "cosmology"
    },
    {
      "field": "physics",
      "origin": "arxiv:gr-qc",
      "subfield": "gravitation"
    },
    {
      "field": "physics",
      "origin": "arxiv:hep-ph",
      "subfield": "high-energy"
    }
  ],
  "title": "Inflationary attractors in metric-affine gravity",
  "title_text": "Inflationary attractors in metric-affine gravity",
  "type": "preprint",
  "updated_at": "2026-11-09T00:20:21Z",
  "url": "https://research.draconitic.com/paper/0t4hqwk3824ys",
  "venue": "arXiv",
  "versions": []
}