{
  "abstract": "We study static, spherically symmetric ultracompact objects in General Relativity with anisotropic stress. Using the covariant anisotropic equation of state and assuming homogeneous density, we construct a mostly analytical model admitting configurations beyond the Buchdahl limit and with compactness arbitrarily close to the black hole value. The solutions exhibit two regimes separated by a critical curve in the parameter space of compactness and anisotropy, associated with the divergence of the central pressure: regular anisotropic configurations with positive central pressure, and singular configurations with negative central pressure for arbitrary anisotropy. In the latter case, we show that introducing a thick shell removes the pressure divergence, yielding regular ultracompact gravastar configurations. We further construct both anisotropic and isotropic gravastar models using this thick-shell construction.",
  "abstract_shown": true,
  "affiliations": [],
  "article_type": "Journal reference: Phys. Rev. D 114, 084009 (2026)",
  "arxiv": "2608.10991",
  "author_total": 3,
  "authors": [
    {
      "name": "Prajwal Hassan Puttasiddappa"
    },
    {
      "name": "Nora Bretón"
    },
    {
      "name": "Santiago Esteban Perez Bergliaffa"
    }
  ],
  "bibtex": "https://research.draconitic.com/paper/432acz8qqaa5t.bib",
  "cited_by": 0,
  "doi": "10.48550/arxiv.2608.10991",
  "fulltext_url": null,
  "id": "432acz8qqaa5t",
  "issns": [],
  "landing_url": "https://arxiv.org/abs/2608.10991",
  "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",
      "gr-qc"
    ]
  ],
  "openalex": null,
  "pdf_url": "https://arxiv.org/pdf/2608.10991",
  "pmcid": null,
  "pmid": null,
  "published": "2026-10-02",
  "publisher": null,
  "ris": "https://research.draconitic.com/paper/432acz8qqaa5t.ris",
  "sources": [
    {
      "first_seen": "2026-10-30T12:27:01Z",
      "native_id": "2608.10991",
      "source": "arxiv",
      "url": "https://arxiv.org/abs/2608.10991"
    }
  ],
  "subjects": [
    {
      "field": "physics",
      "origin": "arxiv:gr-qc",
      "subfield": "gravitation"
    }
  ],
  "title": "Ultracompact anisotropic stars and gravastars in general relativity",
  "title_text": "Ultracompact anisotropic stars and gravastars in general relativity",
  "type": "preprint",
  "updated_at": "2026-10-30T12:27:01Z",
  "url": "https://research.draconitic.com/paper/432acz8qqaa5t",
  "venue": "arXiv",
  "versions": [
    {
      "doi": "10.1103/c3ks-b9g7",
      "pid": null,
      "relation": "published-as",
      "title": null,
      "venue": null
    }
  ]
}