{
  "abstract": "We investigate a particular case of the extended exponential infrared f(T) teleparallel gravity, in which the geometric sector naturally produces an effective dark-energy density that evolves from negative values in the past to positive values at late times. This behaviour could be motivated by observational results providing a compelling motivation for a geometric, sign-changing dark-energy scenario within modified gravity. We demonstrate that the parameter space of the present model contains only six parameters similar to $Λ$CDM. A Markov Chain Monte Carlo (MCMC) analysis using Planck, DESI, and Type Ia supernova data yields a well-constrained transition redshift of $z_{\\rm tr} \\gtrsim 1.62$, accompanied by a transition in the effective equation of state to the phantom regime ($w < -1$) for $z < z_{\\rm tr}$. Since the effective dark energy originates from modified geometric degrees of freedom, no instabilities or violations of energy conditions arise. The model naturally accounts for the $H_0$ tension, where Planck+DESI data combination gives $H_0 = 72.13 \\pm 0.28 \\text{ km s}^{-1} \\text{ Mpc}^{-1}$ in a better agreement with local measurements than $Λ$CDM which gives $H_0 = 68.46 \\pm 0.30 \\text{ km s}^{-1} \\text{ Mpc}^{-1}$. However, the model is disfavored in comparison to $Λ$CDM in terms of the values of $χ^2$ of the bestfit parameters. We discuss the result among other issues related to CMB-BAO tension.",
  "abstract_shown": true,
  "affiliations": [],
  "article_type": null,
  "arxiv": "2609.10560",
  "author_total": 4,
  "authors": [
    {
      "name": "Mohamed Bedair"
    },
    {
      "name": "Mahmoud Hashim"
    },
    {
      "name": "Jackson Levi Said"
    },
    {
      "name": "Waleed El Hanafy"
    }
  ],
  "bibtex": "https://research.draconitic.com/paper/3w76vq1css8tj.bib",
  "cited_by": 0,
  "doi": "10.48550/arxiv.2609.10560",
  "fulltext_url": null,
  "id": "3w76vq1css8tj",
  "issns": [],
  "landing_url": "https://arxiv.org/abs/2609.10560",
  "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": "W7212298359",
  "pdf_url": "https://arxiv.org/pdf/2609.10560",
  "pmcid": null,
  "pmid": null,
  "published": "2026-09-01",
  "publisher": null,
  "ris": "https://research.draconitic.com/paper/3w76vq1css8tj.ris",
  "sources": [
    {
      "first_seen": "2026-10-30T12:20:26Z",
      "native_id": "2609.10560",
      "source": "arxiv",
      "url": "https://arxiv.org/abs/2609.10560"
    }
  ],
  "subjects": [
    {
      "field": "astronomy",
      "origin": "openalex:3103|Cosmology and Gravitation Theories",
      "subfield": "cosmology"
    }
  ],
  "title": "A Six-Parameter Teleparallel Cosmology Beyond $Λ$CDM: Sign-Changing Torsional Dark Energy and Implications for $H_0$",
  "title_text": "A Six-Parameter Teleparallel Cosmology Beyond ΛCDM: Sign-Changing Torsional Dark Energy and Implications for H_0",
  "type": "preprint",
  "updated_at": "2026-10-30T12:20:26Z",
  "url": "https://research.draconitic.com/paper/3w76vq1css8tj",
  "venue": "arXiv",
  "versions": []
}