{
  "abstract": "Current consensus suggests that Type Ia supernova (SN Ia) brightnesses post light-curve standardization correlate with their host-galaxy stellar masses, which must be accounted for to obtain accurate cosmological constraints. For example, Vincenzi et al. (2025) showed that different host-galaxy stellar mass measurements for the same dataset produce redshift-dependent differences of order $\\sim 0.01$ mag, large enough to appreciably shift cosmological constraints. We present internally consistent host-galaxy stellar masses remeasured using aperture photometry and spectral energy distribution (SED) fitting for SN-Unite, which combines the spectroscopic Pantheon+ and the photometric Dark Energy Survey five-year (DES-SN5YR) samples into the largest SN Ia cosmology sample to date, with 2884 likely SNe Ia. We find that photometry and SED fitting choices shift SN-Unite Flat$w$CDM parameters well below statistical uncertainties. Our stellar masses differ from the Pantheon+ data release partly due to a redshift-dependent internal inconsistency within Pantheon+, while remaining largely consistent with the DES-SN5YR (DES-Dovekie) data release. When the Pantheon+ subsample of SN-Unite is combined with Baryon Acoustic Oscillations (BAO) and Cosmic Microwave Background (CMB) measurements, the significance for time-evolving dark energy increases from 3.4$σ$ to 4.0$σ$ based on the maximum a posteriori when our newly derived host-galaxy stellar masses replace the Pantheon+ data-release host-galaxy stellar masses, while DES-Dovekie remains virtually unchanged, consistent with the findings of Hoyt et al. (2026). By remeasuring the host-galaxy stellar masses using a consistent framework throughout the whole sample, we improve the robustness of the SN-Unite cosmological constraints against systematic differences in host-galaxy stellar mass measurements.",
  "abstract_shown": true,
  "affiliations": [],
  "article_type": null,
  "arxiv": "2609.05321",
  "author_total": 25,
  "authors": [
    {
      "name": "J Lee"
    },
    {
      "name": "R Camilleri"
    },
    {
      "name": "T.M Davis"
    },
    {
      "name": "D Rubin"
    },
    {
      "name": "K Bechtol"
    },
    {
      "name": "L Galbany"
    },
    {
      "name": "M Sako"
    },
    {
      "name": "M Sullivan"
    },
    {
      "name": "T.E Müller-Bravo"
    },
    {
      "name": "D Scolnic"
    },
    {
      "name": "M Vincenzi"
    },
    {
      "name": "D Brout"
    },
    {
      "name": "C Lidman"
    },
    {
      "name": "A Möller"
    },
    {
      "name": "P Shah"
    },
    {
      "name": "M Acevedo"
    },
    {
      "name": "P Armstrong"
    },
    {
      "name": "B.A Bassett"
    },
    {
      "name": "R.C Chen"
    },
    {
      "name": "H.T Diehl"
    },
    {
      "name": "J Frieman"
    },
    {
      "name": "K Grech"
    },
    {
      "name": "B Popovic"
    },
    {
      "name": "B.O Sánchez"
    },
    {
      "name": "B.E Tucker"
    }
  ],
  "bibtex": "https://research.draconitic.com/paper/9fga25hf7ffet.bib",
  "cited_by": 0,
  "doi": "10.48550/arxiv.2609.05321",
  "fulltext_url": null,
  "id": "9fga25hf7ffet",
  "issns": [],
  "landing_url": "https://hal.science/hal-05759146v1",
  "language": "en",
  "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"
    ],
    [
      "hal",
      "0.phys"
    ],
    [
      "hal",
      "1.phys.astr"
    ],
    [
      "openalex",
      "3103|Cosmology and Gravitation Theories"
    ]
  ],
  "openalex": "W7211908715",
  "pdf_url": "https://arxiv.org/pdf/2609.05321",
  "pmcid": null,
  "pmid": null,
  "published": "2026-09-09",
  "publisher": null,
  "ris": "https://research.draconitic.com/paper/9fga25hf7ffet.ris",
  "sources": [
    {
      "first_seen": "2026-10-30T12:17:37Z",
      "native_id": "hal-05759146",
      "source": "hal",
      "url": "https://hal.science/hal-05759146v1"
    },
    {
      "first_seen": "2026-10-30T12:20:12Z",
      "native_id": "2609.05321",
      "source": "arxiv",
      "url": "https://arxiv.org/abs/2609.05321"
    }
  ],
  "subjects": [
    {
      "field": "astronomy",
      "origin": "arxiv:astro-ph.CO",
      "subfield": "cosmology"
    },
    {
      "field": "physics",
      "origin": "hal:0.phys",
      "subfield": "general"
    }
  ],
  "title": "Supernovae Unite: Host-Galaxy Mass Measurements of Type Ia Supernovae and Their Impact on Cosmology",
  "title_text": "Supernovae Unite: Host-Galaxy Mass Measurements of Type Ia Supernovae and Their Impact on Cosmology",
  "type": "preprint",
  "updated_at": "2026-10-30T12:20:12Z",
  "url": "https://research.draconitic.com/paper/9fga25hf7ffet",
  "venue": "HAL",
  "versions": []
}