{
  "abstract": "Recent baryon acoustic oscillation measurements from the Dark Energy Spectroscopic Instrument (DESI), combined with supernova observations, show a mild preference for an evolving dark-energy equation of state, in which dark energy remains phantom-like at higher redshift while a transition toward the quintessence regime emerges around $z\\lesssim0.5$. Beyond the monotonic evolution of the equation of state, an oscillatory dark-energy scenario provides a potential alternative realization of dynamical dark energy. We study such an oscillatory scenario within the Einstein-scalar-Gauss-Bonnet gravity framework, where a scalar field with a hybrid exponential-quadratic potential couples nonminimally to the Gauss-Bonnet (GB) invariant. We choose a Gaussian GB coupling function localized around the minimum of the potential. During the late-time epoch, the field thereby oscillates around the potential minimum and eventually exits toward a stable de Sitter attractor phase. In the minimally coupled limit, the effective equation of state oscillates in the quintessence regime at low redshift, $z\\sim0$, without crossing the phantom divide. The nonminimal coupling amplifies the oscillations and drives the effective equation of state across the phantom divide multiple times. Although a sufficiently strong coupling can induce negative scalar and tensor sound speeds, rendering the perturbation modes unstable. We identify a region of parameter space in which the model undergoes multiple phantom crossings while remaining free of ghost and gradient instabilities and approaching a stable de Sitter attractor in the future.",
  "abstract_shown": true,
  "affiliations": [],
  "article_type": null,
  "arxiv": "2609.37437",
  "author_total": 2,
  "authors": [
    {
      "name": "Saddam Hussain"
    },
    {
      "name": "Sandip Biswas"
    }
  ],
  "bibtex": "https://research.draconitic.com/paper/bhw8ezqxx95d4.bib",
  "cited_by": 0,
  "doi": "10.48550/arxiv.2609.37437",
  "fulltext_url": null,
  "id": "bhw8ezqxx95d4",
  "issns": [],
  "landing_url": "https://arxiv.org/abs/2609.37437",
  "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",
      "3103|Cosmology and Gravitation Theories"
    ]
  ],
  "openalex": "W7214989177",
  "pdf_url": "https://arxiv.org/pdf/2609.37437",
  "pmcid": null,
  "pmid": null,
  "published": "2026-09-29",
  "publisher": null,
  "ris": "https://research.draconitic.com/paper/bhw8ezqxx95d4.ris",
  "sources": [
    {
      "first_seen": "2026-10-30T12:25:31Z",
      "native_id": "2609.37437",
      "source": "arxiv",
      "url": "https://arxiv.org/abs/2609.37437"
    }
  ],
  "subjects": [
    {
      "field": "physics",
      "origin": "arxiv:gr-qc",
      "subfield": "gravitation"
    }
  ],
  "title": "Oscillatory dark energy with phantom crossings in Einstein-Gauss-Bonnet gravity",
  "title_text": "Oscillatory dark energy with phantom crossings in Einstein-Gauss-Bonnet gravity",
  "type": "preprint",
  "updated_at": "2026-10-30T12:25:31Z",
  "url": "https://research.draconitic.com/paper/bhw8ezqxx95d4",
  "venue": "arXiv",
  "versions": []
}