{
  "abstract": "We study the cosmological dynamics of a general class of viscous dark matter models using a dynamical system analysis. In the Eckart formalism, these viscous cosmologies are characterized by a dimensionless bulk viscous pressure $Ω_Π\\equiv Ω_Π(Ω_m)$, where $Ω_m$ is the matter density parameter. Our analysis demonstrates that a viable early radiation era requires the complete absence of viscosity, a proper matter-dominated epoch demands a small viscous pressure, and the only physically admissible late-time attractor is the cosmological constant-dominated fixed point; consequently, the background expansion must closely track standard $Λ$CDM evolution. We validate these general results using the power-law parameterization $Ω_Π= -\\hatξ_0 Ω_m^s$, where $\\hatξ_0$ and $s$ are real parameters; for $s \\geq 1$ and $\\hatξ_0 \\ll 1$, the model reproduces the $Λ$CDM background, while for $s < 1$ the system encounters a past-time integration boundary where the dark matter density transitions into negative values and its viscous pressure evaluates to nonphysical complex numbers. Since the background expansion essentially duplicates $Λ$CDM, the model is unlikely to resolve the $H_0$ tension. However, large differences arise at the linear perturbative level; indeed, on sub-horizon scales, bulk viscosity causes a scale-dependent dissipative drag on the matter density fluctuations; this increases the Hubble friction, offering a channel to suppress structure growth.",
  "abstract_shown": true,
  "affiliations": [],
  "article_type": null,
  "arxiv": "2610.35405",
  "author_total": 3,
  "authors": [
    {
      "name": "David R. Moreno"
    },
    {
      "name": "J. Bayron Orjuela-Quintana"
    },
    {
      "name": "Yeinzon Rodriguez"
    }
  ],
  "bibtex": "https://research.draconitic.com/paper/afvcv6fqgwr4c.bib",
  "cited_by": 0,
  "doi": "10.48550/arxiv.2610.35405",
  "fulltext_url": null,
  "id": "afvcv6fqgwr4c",
  "issns": [],
  "landing_url": "https://arxiv.org/abs/2610.35405",
  "language": null,
  "licence": "LicenseRef-arXiv-nonexclusive-1.0",
  "licence_label": "arXiv licence",
  "licence_source": "article",
  "licence_url": "http://arxiv.org/licenses/nonexclusive-distrib/1.0/",
  "metadata_licence": "CC0-1.0",
  "native_subjects": [
    [
      "arxiv",
      "gr-qc"
    ],
    [
      "openalex",
      "3103|Cosmology and Gravitation Theories"
    ]
  ],
  "openalex": "W7223814033",
  "pdf_url": "https://arxiv.org/pdf/2610.35405",
  "pmcid": null,
  "pmid": null,
  "published": "2026-10-26",
  "publisher": null,
  "ris": "https://research.draconitic.com/paper/afvcv6fqgwr4c.ris",
  "sources": [
    {
      "first_seen": "2026-10-30T12:35:35Z",
      "native_id": "2610.35405",
      "source": "arxiv",
      "url": "https://arxiv.org/abs/2610.35405"
    }
  ],
  "subjects": [
    {
      "field": "physics",
      "origin": "arxiv:gr-qc",
      "subfield": "gravitation"
    }
  ],
  "title": "Phase-Space Constraints on a General Class of Eckart-like Viscous Cosmologies",
  "title_text": "Phase-Space Constraints on a General Class of Eckart-like Viscous Cosmologies",
  "type": "preprint",
  "updated_at": "2026-10-30T12:35:35Z",
  "url": "https://research.draconitic.com/paper/afvcv6fqgwr4c",
  "venue": "arXiv",
  "versions": []
}