{
  "abstract": "Diffusion functions in unimodular gravity induce a dynamical effective cosmological constant, providing an appealing framework in light of recent DESI observations. In this work, we investigate the observational viability of a general class of diffusion models using baryon acoustic oscillation measurements from DESI DR2, Type Ia supernova compilations (Pantheon+, DES-Dovekie, and DESY5), and Cosmic Chronometer data. We find that diffusion models systematically achieve lower best-fit $χ^{2}$ values than $Λ$CDM across all dataset combinations considered, indicating a modest but persistent improvement in goodness of fit. Nevertheless, the reduction in $χ^{2}$ is insufficient to offset the larger parameter space, leading standard information criteria to favor the simpler $Λ$CDM model. Despite this result, all dataset combinations consistently prefer a nonvanishing diffusion contribution corresponding to approximately $20\\%$ of the present dark-energy budget, with a posterior probability $P(f_Q>0.05) =96.78\\%$. From an observational perspective, diffusion models therefore remain a viable extension of the standard cosmological scenario and motivate the exploration of simpler diffusion parameterizations, particularly in light of upcoming high-precision cosmological surveys.",
  "abstract_shown": true,
  "affiliations": [],
  "article_type": null,
  "arxiv": "2609.10574",
  "author_total": 3,
  "authors": [
    {
      "name": "Gabriel Gomez"
    },
    {
      "name": "Guillermo Palma"
    },
    {
      "name": "Norman Cruz"
    }
  ],
  "bibtex": "https://research.draconitic.com/paper/ee89z9389sxv0.bib",
  "cited_by": 0,
  "doi": "10.48550/arxiv.2609.10574",
  "fulltext_url": null,
  "id": "ee89z9389sxv0",
  "issns": [],
  "landing_url": "https://arxiv.org/abs/2609.10574",
  "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": null,
  "pdf_url": "https://arxiv.org/pdf/2609.10574",
  "pmcid": null,
  "pmid": null,
  "published": "2026-09-03",
  "publisher": null,
  "ris": "https://research.draconitic.com/paper/ee89z9389sxv0.ris",
  "sources": [
    {
      "first_seen": "2026-10-30T12:20:26Z",
      "native_id": "2609.10574",
      "source": "arxiv",
      "url": "https://arxiv.org/abs/2609.10574"
    }
  ],
  "subjects": [
    {
      "field": "physics",
      "origin": "arxiv:physics.gen-ph",
      "subfield": "general"
    }
  ],
  "title": "Observational constraints on Diffusion Cosmologies in Unimodular Gravity from DESI DR2",
  "title_text": "Observational constraints on Diffusion Cosmologies in Unimodular Gravity from DESI DR2",
  "type": "preprint",
  "updated_at": "2026-10-30T12:20:26Z",
  "url": "https://research.draconitic.com/paper/ee89z9389sxv0",
  "venue": "arXiv",
  "versions": []
}