{
  "abstract": "We present a first background-level observational test of a thermogravity theory in which the Einstein equations are clipped to a trace-free version, the cosmological constant $Λ$ does not gravitate, and controlled violations of energy conservation obstruct the usual reinstatement of $Λ$ as an integration constant. We therefore set $Λ=0$ and ask whether late-time acceleration can instead be generated solely by energy non-conservation, with no extra background parameter relative to flat $Λ\\mathrm{CDM}$. We contrast a minimal universal implementation with a model in which only CDM partakes in non-conservation. The universal model is strongly disfavored when combining Supernovae and BAO distances, with the inclusion of DESI BAO worsening the fit by $Δχ^2\\simeq 51$ relative to $Λ\\mathrm{CDM}$, because matter creation ties the intermediate-redshift normalization of $H(z)$ too rigidly to the present acceleration. This conclusion, however, should be interpreted with caution, since universal non-conservation would modify the observational dictionary itself. By contrast, restricting non-conservation to CDM leaves baryonic and photon observables unaffected at the background level and therefore allows a self-contained analysis. The resulting $ξ\\mathrm{CDM}$ model, which can be thought of as a one parameter extension of $Λ\\mathrm{CDM}$, provides an improved fit relative to $Λ\\mathrm{CDM}$ for the background dataset combinations considered, with improvements reaching $Δχ^2=-4.85$ and a maximum Bayesian preference of $\\ln\\mathcal{B}=2.77$. However, when the BAO ruler is calibrated using BBN or CMB information, the reduced effective early-time CDM density increases the sound horizon and drives $H_0$ towards lower values, thereby increasing rather than alleviating the tension with the distance-ladder calibration.",
  "abstract_shown": true,
  "affiliations": [],
  "article_type": null,
  "arxiv": "2609.29206",
  "author_total": 4,
  "authors": [
    {
      "name": "Dong Ha Lee"
    },
    {
      "name": "João Magueijo"
    },
    {
      "name": "Carsten van de Bruck"
    },
    {
      "name": "Eleonora Di Valentino"
    }
  ],
  "bibtex": "https://research.draconitic.com/paper/6n9wdr8pxta8x.bib",
  "cited_by": 0,
  "doi": "10.48550/arxiv.2609.29206",
  "fulltext_url": null,
  "id": "6n9wdr8pxta8x",
  "issns": [],
  "landing_url": "https://arxiv.org/abs/2609.29206",
  "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",
      "astro-ph.CO"
    ],
    [
      "arxiv",
      "gr-qc"
    ],
    [
      "arxiv",
      "hep-ph"
    ],
    [
      "openalex",
      "3103|Cosmology and Gravitation Theories"
    ]
  ],
  "openalex": "W7214361565",
  "pdf_url": "https://arxiv.org/pdf/2609.29206",
  "pmcid": null,
  "pmid": null,
  "published": "2026-09-24",
  "publisher": null,
  "ris": "https://research.draconitic.com/paper/6n9wdr8pxta8x.ris",
  "sources": [
    {
      "first_seen": "2026-10-30T12:24:11Z",
      "native_id": "2609.29206",
      "source": "arxiv",
      "url": "https://arxiv.org/abs/2609.29206"
    }
  ],
  "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": "Testing cosmic acceleration from thermogravity without vacuum energy",
  "title_text": "Testing cosmic acceleration from thermogravity without vacuum energy",
  "type": "preprint",
  "updated_at": "2026-10-30T12:24:11Z",
  "url": "https://research.draconitic.com/paper/6n9wdr8pxta8x",
  "venue": "arXiv",
  "versions": []
}