{
  "abstract": "The recent DESI DR2 results preference for a time-varying dark-energy equation of state, together with the long-standing difficulty of explaining why an initially anisotropic universe should evolve toward isotropy, motivates the study of interacting dark-sector models in anisotropic backgrounds. We investigate the dynamics of Bianchi type-IX cosmologies containing pressureless dark matter coupled to dark energy in the form of a quintessence scalar field $ϕ$ with exponential potential $V(ϕ)=V_0\\,e^{-λϕ}$. Energy exchange between the two dark components is mediated by the scalar field through the interaction term $Q=κβ\\dotϕ\\,ρ_{\\rm DM}$, where $κ^2=8πG$ and $β$ is a dimensionless coupling. Because Bianchi~IX models generically recollapse, the Hubble scalar $H$ vanishes at the moment of maximum expansion, where the expansion-normalized variables of the standard Wainwright--Ellis formalism diverge. We therefore adopt the $D$-normalized phase-space formalism of Hewitt, Uggla, and Wainwright, which compactifies the state space and remains regular through the recollapse, including the moment of maximum expansion at which $H = 0$. Together with the modified conservation equations for the two dark components, the Einstein equation reduces to a closed autonomous polynomial dynamical system, whose fixed points we classify by linear stability analysis, supplemented by center-manifold theory for the non-hyperbolic points. The fixed points shows the kinetic-dominated, coupling modified matter dominated, curvature scalar, scalar field dominated and coupled scaling families; the last is the anisotropic analogue of the Amendola scaling attractor. Restricting to the initially expanding, isotropizing trajectories, we map the region of the $(λ,β)$ plane in which anisotropic Bianchi~IX models approach an accelerating Friedmann--Robertson--Walker state.",
  "abstract_shown": true,
  "affiliations": [],
  "article_type": null,
  "arxiv": "2610.35953",
  "author_total": 3,
  "authors": [
    {
      "name": "Ashmita"
    },
    {
      "name": "Jaturaporn Watanakampolkij"
    },
    {
      "name": "Daris Samart"
    }
  ],
  "bibtex": "https://research.draconitic.com/paper/2mjpdctnz8v5h.bib",
  "cited_by": 0,
  "doi": "10.48550/arxiv.2610.35953",
  "fulltext_url": null,
  "id": "2mjpdctnz8v5h",
  "issns": [],
  "landing_url": "https://arxiv.org/abs/2610.35953",
  "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",
      "physics.gen-ph"
    ],
    [
      "openalex",
      "3103|Cosmology and Gravitation Theories"
    ]
  ],
  "openalex": "W7224086347",
  "pdf_url": "https://arxiv.org/pdf/2610.35953",
  "pmcid": null,
  "pmid": null,
  "published": "2026-10-24",
  "publisher": null,
  "ris": "https://research.draconitic.com/paper/2mjpdctnz8v5h.ris",
  "sources": [
    {
      "first_seen": "2026-10-30T12:35:50Z",
      "native_id": "2610.35953",
      "source": "arxiv",
      "url": "https://arxiv.org/abs/2610.35953"
    }
  ],
  "subjects": [
    {
      "field": "astronomy",
      "origin": "openalex:3103|Cosmology and Gravitation Theories",
      "subfield": "cosmology"
    }
  ],
  "title": "Dynamical systems analysis of Bianchi type-IX cosmology with a scalar field mediated dark sector interaction",
  "title_text": "Dynamical systems analysis of Bianchi type-IX cosmology with a scalar field mediated dark sector interaction",
  "type": "preprint",
  "updated_at": "2026-10-30T12:35:50Z",
  "url": "https://research.draconitic.com/paper/2mjpdctnz8v5h",
  "venue": "arXiv",
  "versions": []
}