{
  "abstract": "We present exact analytic solutions for the linear dynamics of a two-field inflationary system in which the primordial curvature perturbation $ζ$ is coupled to an isocurvature perturbation $σ$ of entropy mass $μ$. The solutions are valid for arbitrary values of $μ$ and the dimensionless interaction strength $λ$. They therefore provide analytic control over the strong mixing regime in which $ζ$ interacts with light isocurvature fields, commonly associated with rapid-turn inflation. As a first application, we derive the amplitude of the primordial power spectrum in closed form, obtaining an expression that interpolates between the weakly mixed, strongly mixed, light-field, and heavy-field regimes. These results open the way to analytic studies of multifield observables beyond the power spectrum, including non-Gaussianity, particle production, and loop corrections.",
  "abstract_shown": true,
  "affiliations": [],
  "article_type": null,
  "arxiv": "2606.18248",
  "author_total": 4,
  "authors": [
    {
      "name": "Javier Huenupi"
    },
    {
      "name": "Claudio Muñoz"
    },
    {
      "name": "Gonzalo A. Palma"
    },
    {
      "name": "Spyros Sypsas"
    }
  ],
  "bibtex": "https://research.draconitic.com/paper/e13006fbr0fzq.bib",
  "cited_by": 0,
  "doi": "10.48550/arxiv.2606.18248",
  "fulltext_url": null,
  "id": "e13006fbr0fzq",
  "issns": [],
  "landing_url": "https://arxiv.org/abs/2606.18248",
  "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"
    ],
    [
      "arxiv",
      "hep-th"
    ],
    [
      "openalex",
      "3103|Cosmology and Gravitation Theories"
    ]
  ],
  "openalex": "W7165001251",
  "pdf_url": "https://arxiv.org/pdf/2606.18248",
  "pmcid": null,
  "pmid": null,
  "published": "2026-10-27",
  "publisher": null,
  "ris": "https://research.draconitic.com/paper/e13006fbr0fzq.ris",
  "sources": [
    {
      "first_seen": "2026-10-30T12:35:50Z",
      "native_id": "2606.18248",
      "source": "arxiv",
      "url": "https://arxiv.org/abs/2606.18248"
    }
  ],
  "subjects": [
    {
      "field": "astronomy",
      "origin": "arxiv:astro-ph.CO",
      "subfield": "cosmology"
    },
    {
      "field": "physics",
      "origin": "arxiv:hep-ph",
      "subfield": "high-energy"
    }
  ],
  "title": "Pushing the Primordial Frontier: Exact Linear Solutions in Multifield Inflation",
  "title_text": "Pushing the Primordial Frontier: Exact Linear Solutions in Multifield Inflation",
  "type": "preprint",
  "updated_at": "2026-10-30T12:35:50Z",
  "url": "https://research.draconitic.com/paper/e13006fbr0fzq",
  "venue": "arXiv",
  "versions": []
}