{
  "abstract": "We investigate a particular case of the New Exponential Infrared $f(T)$ teleparallel gravity model with the same number of free parameters as the standard $Λ$CDM model. Remarkably, due to the two real branches of the Lambert function $W$, the model admits two distinct cosmological solutions, denoted by $f^{(I)}$CDM and $f^{(II)}$CDM. The former exhibits a late-time phantom crossing, whereas the latter predicts an effective dark-energy density evolving from negative to positive values. Using a Markov Chain Monte Carlo analysis of the Planck CMB, DESI BAO, and Type Ia supernova data, we find that the $f^{(II)}$CDM branch develops a bimodal posterior distribution in the primordial parameters $A_s$ and $τ_{ reio}$ for the Planck-only dataset. We show that this bimodality originates from the tension between the low-$\\ell$ TT and EE likelihoods, which becomes pronounced in models exhibiting a significantly enhanced late ISW contribution relative to the $Λ$CDM model. Moreover, the inclusion of background observations drives this branch toward cosmologically unacceptable parameter values, rendering it observationally unviable. The $f^{(I)}$CDM branch, on the other hand, remains observationally viable, yielding $H_0=73.43\\pm0.69~\\mathrm{km\\,s^{-1}\\,Mpc^{-1}}$ for the Planck-only dataset and $H_0=72.55\\pm0.32~\\mathrm{km\\,s^{-1}\\,Mpc^{-1}}$ after including DESI, substantially alleviating the Hubble tension. Although this branch provides a slightly better fit than $Λ$CDM for Planck-only data, the addition of background observations reverses this preference in favor of the standard $Λ$CDM model. These results show that the cosmological viability of this model critically depends on the choice of the Lambert $W$ branch, with only the $f^{(I)}$CDM solution remaining compatible with current cosmological observations.",
  "abstract_shown": true,
  "affiliations": [],
  "article_type": null,
  "arxiv": "2610.23956",
  "author_total": 1,
  "authors": [
    {
      "name": "Mohamed bedair"
    }
  ],
  "bibtex": "https://research.draconitic.com/paper/aqwt2jb511ch9.bib",
  "cited_by": 0,
  "doi": "10.48550/arxiv.2610.23956",
  "fulltext_url": null,
  "id": "aqwt2jb511ch9",
  "issns": [],
  "landing_url": "https://arxiv.org/abs/2610.23956",
  "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": "W7222994273",
  "pdf_url": "https://arxiv.org/pdf/2610.23956",
  "pmcid": null,
  "pmid": null,
  "published": "2026-10-09",
  "publisher": null,
  "ris": "https://research.draconitic.com/paper/aqwt2jb511ch9.ris",
  "sources": [
    {
      "first_seen": "2026-10-30T12:30:52Z",
      "native_id": "2610.23956",
      "source": "arxiv",
      "url": "https://arxiv.org/abs/2610.23956"
    }
  ],
  "subjects": [
    {
      "field": "astronomy",
      "origin": "openalex:3103|Cosmology and Gravitation Theories",
      "subfield": "cosmology"
    }
  ],
  "title": "Two Cosmological Histories in a New Exponential Infrared $f(T)$ Teleparallel Gravity: Implications for the Hubble Tension and the Low-$\\ell$ Planck TT--EE Tension",
  "title_text": "Two Cosmological Histories in a New Exponential Infrared f(T) Teleparallel Gravity: Implications for the Hubble Tension and the Low-ℓ Planck TT--EE Tension",
  "type": "preprint",
  "updated_at": "2026-10-30T12:33:41Z",
  "url": "https://research.draconitic.com/paper/aqwt2jb511ch9",
  "venue": "arXiv",
  "versions": []
}