{
  "abstract": "Recent DESI observations hint at a preference for dynamical dark energy with an equation of state (EoS) that crosses the phantom divide at $w=-1$. In this work, we investigate \\textit{metastable} dark energy (DE) on the minimal phantom brane. Braneworld effects lead to $w < -1$ at early times, whereas metastable decay of DE results in $w > -1$ at late times. We consider three metastable decay prescriptions on the phantom brane: an exponentially decaying DE component (M1), decay of DE into non-baryonic dark matter (M2), and decay into dark radiation (M3). Using CMB observations, DESI DR2 BAO measurements, and the DES-Dovekie Type Ia supernova sample, we compare these models with $Λ$CDM, the Chevallier--Polarski--Linder (CPL) parametrization, and the minimal phantom-brane model with a non-decaying $Λ$. We find that metastable models on the brane are preferred over $Λ$CDM, their decay rates being $Γ/H_0=0.362\\pm0.086$, $0.539\\pm0.125$, and $0.483\\pm0.112$ for M1, M2, and M3, respectively. Best fits of metastable models improve over $Λ$CDM by $Δχ^2_{\\rm MAP}=-17.14$, $-18.76$, and $-18.22$, while the corresponding $Δ{\\rm DIC}$ values are $-8.66$, $-9.63$, and $-6.56$. Braneworld screening drives effective phantom behaviour at $z\\gtrsim0.4$, while DE decay drives the EoS toward non-phantom values closer to the present epoch, with the phantom divide $w=-1$ being crossed at $z \\simeq 0.3$--$0.4$. These results show that the interplay between metastable decay and phantom-brane screening provides a simple physical mechanism for an effective crossing of the phantom divide consistent with DESI observations.",
  "abstract_shown": true,
  "affiliations": [],
  "article_type": null,
  "arxiv": "2609.39039",
  "author_total": 4,
  "authors": [
    {
      "name": "Purba Mukherjee"
    },
    {
      "name": "Arman Shafieloo"
    },
    {
      "name": "Varun Sahni"
    },
    {
      "name": "Yuri Shtanov"
    }
  ],
  "bibtex": "https://research.draconitic.com/paper/ehjp6pcywfts9.bib",
  "cited_by": 0,
  "doi": "10.48550/arxiv.2609.39039",
  "fulltext_url": null,
  "id": "ehjp6pcywfts9",
  "issns": [],
  "landing_url": "https://arxiv.org/abs/2609.39039",
  "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",
      "astro-ph.CO"
    ],
    [
      "arxiv",
      "gr-qc"
    ],
    [
      "arxiv",
      "hep-ph"
    ],
    [
      "arxiv",
      "hep-th"
    ],
    [
      "openalex",
      "3103|Cosmology and Gravitation Theories"
    ]
  ],
  "openalex": "W7215042181",
  "pdf_url": "https://arxiv.org/pdf/2609.39039",
  "pmcid": null,
  "pmid": null,
  "published": "2026-09-30",
  "publisher": null,
  "ris": "https://research.draconitic.com/paper/ehjp6pcywfts9.ris",
  "sources": [
    {
      "first_seen": "2026-10-30T12:25:49Z",
      "native_id": "2609.39039",
      "source": "arxiv",
      "url": "https://arxiv.org/abs/2609.39039"
    }
  ],
  "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": "Metastable Dark Energy on the Phantom Brane",
  "title_text": "Metastable Dark Energy on the Phantom Brane",
  "type": "preprint",
  "updated_at": "2026-10-30T12:25:49Z",
  "url": "https://research.draconitic.com/paper/ehjp6pcywfts9",
  "venue": "arXiv",
  "versions": []
}