{
  "abstract": "We present a multi-redshift Baryon Acoustic Oscillations (BAO) analysis of the DESI Data Release 2 (DR2) Lyman-$α$ (Ly$α$) forest, splitting the forest auto-correlation and its cross-correlation with quasars into three redshift bins. We obtain BAO measurements at effective redshifts $z_{\\rm eff} = 2.13$, $2.40$, and $2.81$ with $\\sim2.0$--$2.5\\%$ precision per bin in the radial and transverse directions, corresponding to $\\sim1.1$--$1.2\\%$ precision for the isotropic BAO measurement. Using the same data products and modeling framework as the DESI DR2 Ly$α$ BAO analysis, we validate the pipeline on $400$ synthetic datasets and find unbiased BAO recovery with well-calibrated uncertainties. The measurements show an increase in the isotropic dilation parameter $D_V/r_d$ from $30.26\\pm0.39$ to $32.22\\pm0.47$ and in the Alcock-Paczyński parameter $D_M/D_H$ from $3.96\\pm0.15$ to $5.63^{+0.22}_{-0.24}$. The Hubble distance $D_H/r_d$ decreases from $9.40\\pm0.20$ to $7.22\\pm0.17$, providing a direct measurement of the expansion history consistent with $Λ$CDM and the expected matter-dominated scaling, with $H(z)\\propto(1+z)^n$ giving $n=1.34\\pm0.16$. The redshift split also provides a self-consistent measurement of clustering evolution: the Ly$α$ forest bias evolves as $(1+z)^γ$ with $γ_α=3.05\\pm0.16$, the RSD parameter has a redshift evolution described by $γ_β=-0.97\\pm0.26$, and the quasar bias evolves with $γ_Q=1.56\\pm0.23$, consistent with independent quasar clustering measurements. Combining these three-bin BAO measurements with DESI DR2 galaxy and quasar BAO measurements yields cosmological constraints consistent with the single-bin Ly$α$ BAO analysis in flat $Λ$CDM and $w_0w_a$CDM and improves curvature constraints by $\\sim12\\%$ in $Λ$CDM$+Ω_\\mathrm{K}$.",
  "abstract_shown": true,
  "affiliations": [],
  "article_type": null,
  "arxiv": "2607.19619",
  "author_total": 63,
  "authors": [
    {
      "name": "Hiram K. Herrera-Alcantar"
    },
    {
      "name": "Julien Guy"
    },
    {
      "name": "Alma X. Gonzalez-Morales"
    },
    {
      "name": "Eric Armengaud"
    },
    {
      "name": "Edwin L. Pérez-Ochoa"
    },
    {
      "name": "Cristhian Garcia-Quintero"
    },
    {
      "name": "J. Aguilar"
    },
    {
      "name": "S. Ahlen"
    },
    {
      "name": "F. Beutler"
    },
    {
      "name": "D. Bianchi"
    },
    {
      "name": "A. Brodzeller"
    },
    {
      "name": "D. Brooks"
    },
    {
      "name": "E. Chaussidon"
    },
    {
      "name": "T. Claybaugh"
    },
    {
      "name": "A. Cuceu"
    },
    {
      "name": "K. S. Dawson"
    },
    {
      "name": "A. de la Macorra"
    },
    {
      "name": "Arjun Dey"
    },
    {
      "name": "S. Ferraro"
    },
    {
      "name": "A. Font-Ribera"
    },
    {
      "name": "J. E. Forero-Romero"
    },
    {
      "name": "E. Gaztañaga"
    },
    {
      "name": "G. Gutierrez"
    },
    {
      "name": "C. Hahn"
    },
    {
      "name": "K. Honscheid"
    },
    {
      "name": "D. Huterer"
    },
    {
      "name": "M. Ishak"
    },
    {
      "name": "T. Karim"
    },
    {
      "name": "R. Kehoe"
    },
    {
      "name": "D. Kirkby"
    },
    {
      "name": "A. Kremin"
    },
    {
      "name": "O. Lahav"
    },
    {
      "name": "A. Lambert"
    },
    {
      "name": "M. Landriau"
    },
    {
      "name": "L. Le Guillou"
    },
    {
      "name": "M. Manera"
    },
    {
      "name": "P. Martini"
    },
    {
      "name": "A. Meisner"
    },
    {
      "name": "R. Miquel"
    },
    {
      "name": "J. Moustakas"
    },
    {
      "name": "A. Muñoz-Gutiérrez"
    },
    {
      "name": "S. Nadathur"
    },
    {
      "name": "G. Niz"
    },
    {
      "name": "E. Paillas"
    },
    {
      "name": "N. Palanque-Delabrouille"
    },
    {
      "name": "W. J. Percival"
    },
    {
      "name": "C. Poppett"
    },
    {
      "name": "F. Prada"
    },
    {
      "name": "I. Pérez-Ràfols"
    },
    {
      "name": "C. Ravoux"
    },
    {
      "name": "G. Rossi"
    },
    {
      "name": "R. Ruggeri"
    },
    {
      "name": "L. Samushia"
    },
    {
      "name": "E. Sanchez"
    },
    {
      "name": "C. Saulder"
    },
    {
      "name": "D. Schlegel"
    },
    {
      "name": "M. Schubnell"
    },
    {
      "name": "H. Seo"
    },
    {
      "name": "J. Silber"
    },
    {
      "name": "G. Tarlé"
    }
  ],
  "bibtex": "https://research.draconitic.com/paper/24htz4y1jwrxd.bib",
  "cited_by": 0,
  "doi": "10.48550/arxiv.2607.19619",
  "fulltext_url": null,
  "id": "24htz4y1jwrxd",
  "issns": [],
  "landing_url": "https://arxiv.org/abs/2607.19619",
  "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"
    ]
  ],
  "openalex": null,
  "pdf_url": "https://arxiv.org/pdf/2607.19619",
  "pmcid": null,
  "pmid": null,
  "published": "2026-11-04",
  "publisher": null,
  "ris": "https://research.draconitic.com/paper/24htz4y1jwrxd.ris",
  "sources": [
    {
      "first_seen": "2026-11-06T18:21:30Z",
      "native_id": "2607.19619",
      "source": "arxiv",
      "url": "https://arxiv.org/abs/2607.19619"
    }
  ],
  "subjects": [
    {
      "field": "astronomy",
      "origin": "arxiv:astro-ph.CO",
      "subfield": "cosmology"
    }
  ],
  "title": "Probing the matter-dominated expansion with multi-redshift Lyman-$α$ BAO from DESI DR2",
  "title_text": "Probing the matter-dominated expansion with multi-redshift Lyman-α BAO from DESI DR2",
  "type": "preprint",
  "updated_at": "2026-11-09T00:20:33Z",
  "url": "https://research.draconitic.com/paper/24htz4y1jwrxd",
  "venue": "arXiv",
  "versions": []
}