{
  "abstract": "Recent measurements from DESI baryon acoustic oscillations (BAO) have reported a moderate preference for dynamical dark energy, challenging the $Λ$CDM paradigm. Nonetheless, such a trend could reflect a tension between the shape and the offset of the Hubble diagrams predicted by current BAO and Type Ia supernovae (SN) data, which may underpin a possible breakdown of the cosmic distance duality relation linking luminosity distances $D_{\\rm L}$ and angular-diameter distances $D_{\\rm A}$. We explore this possibility by parametrizing deviations from this relation as $η(z)\\equiv D_{\\rm L}/[{(1+z)}^2D_{\\rm A}]=α{(1+z)}^\\varepsilon$, and investigate how the preference for a Chevallier-Polarski-Linder (CPL) dynamical dark energy is modified once $\\varepsilon\\neq0$ is allowed. Using DESI DR2 and uncalibrated SN data (Pantheon$+$, DES-Dovekie, Union3, and Union3.1), we find that allowing $\\varepsilon$ to vary freely in both $Λ$CDM and CPL reduces the CPL preference with respect to $Λ$CDM by a larger amount than the addition of spatial curvature $Ω_k$; only Union3.1 exhibits comparable reductions. We also find that the preference reduction is robust to alternative $η(z)$ parametrizations, and that the $η(z)$ constraints remain stable under the removal of BAO tracers or low-redshift cutoffs for Pantheon$+$, whereas the DES-Dovekie preference largely disappears once $z<0.1$ SN are removed. In a separate calibrated analysis, illustrative Planck sound-horizon and SH0ES absolute-magnitude priors give $α\\simeq0.942\\pm0.014$, quantifying the normalization mismatch under those assumptions. We also discuss photon-loss and varying-$G$ interpretations: ordinary positive opacity cannot explain the negative central tilts $\\varepsilon$ found for a $Λ$CDM background, while local gravity tests strongly constrain the illustrative unscreened varying-$G$ scenario.",
  "abstract_shown": true,
  "affiliations": [],
  "article_type": null,
  "arxiv": "2610.16496",
  "author_total": 3,
  "authors": [
    {
      "name": "Mikel Artola"
    },
    {
      "name": "Stéphane Fay"
    },
    {
      "name": "Leandros Perivolaropoulos"
    }
  ],
  "bibtex": "https://research.draconitic.com/paper/fkj51exynqeqb.bib",
  "cited_by": 0,
  "doi": "10.48550/arxiv.2610.16496",
  "fulltext_url": null,
  "id": "fkj51exynqeqb",
  "issns": [],
  "landing_url": "https://arxiv.org/abs/2610.16496",
  "language": null,
  "licence": "LicenseRef-arXiv-nonexclusive-1.0",
  "licence_label": "arXiv licence",
  "licence_source": "article",
  "licence_url": "http://arxiv.org/licenses/nonexclusive-distrib/1.0/",
  "metadata_licence": "CC0-1.0",
  "native_subjects": [
    [
      "arxiv",
      "astro-ph.CO"
    ],
    [
      "arxiv",
      "gr-qc"
    ],
    [
      "arxiv",
      "hep-ph"
    ],
    [
      "arxiv",
      "hep-th"
    ],
    [
      "openalex",
      "3103|Cosmology and Gravitation Theories"
    ]
  ],
  "openalex": "W7221763044",
  "pdf_url": "https://arxiv.org/pdf/2610.16496",
  "pmcid": null,
  "pmid": null,
  "published": "2026-10-20",
  "publisher": null,
  "ris": "https://research.draconitic.com/paper/fkj51exynqeqb.ris",
  "sources": [
    {
      "first_seen": "2026-10-30T12:34:18Z",
      "native_id": "2610.16496",
      "source": "arxiv",
      "url": "https://arxiv.org/abs/2610.16496"
    }
  ],
  "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": "Sensitivity of calibration-free DESI DR2 BAO--supernova constraints to a distance-duality tilt",
  "title_text": "Sensitivity of calibration-free DESI DR2 BAO--supernova constraints to a distance-duality tilt",
  "type": "preprint",
  "updated_at": "2026-10-30T12:34:18Z",
  "url": "https://research.draconitic.com/paper/fkj51exynqeqb",
  "venue": "arXiv",
  "versions": []
}