{
  "abstract": "We apply the Gaussian covariance formalism to develop a semi-analytical covariance model for the joint analysis of pre-reconstruction, post-reconstruction, and cross full-shape galaxy power spectra. We model the reconstruction-reduced, scale-dependent cross shot noise using displacement-field statistics and introduce a new estimator that directly measures this term. Using the measured power spectra and the modeled shot-noise predictions as inputs, we construct the Gaussian covariance while accounting for correlations between the pre- and post-reconstruction density fields. We validate the resulting semi-analytical Gaussian covariance against mock catalogues. Using emulator-based parameter inference, we demonstrate that the semi-analytical Gaussian covariance adequately captures the dominant contribution to the covariance structure of the full data vector ($P_{\\ell}^{\\rm pre}, P_{\\ell}^{\\rm post}, P_{\\ell}^{\\rm cross}$). For the joint fit to these three power spectra, it yields cosmological constraints consistent with those obtained using the mock-based numerical covariance over the adopted fitting ranges: $k_{\\rm max}=0.18\\,h\\,{\\rm Mpc}^{-1}$ for $P_{\\rm pre}$ and $P_{\\rm post}$, and $k_{\\rm max}=0.12\\,h\\,{\\rm Mpc}^{-1}$ for $P_{\\rm cross}$.",
  "abstract_shown": true,
  "affiliations": [],
  "article_type": null,
  "arxiv": "2608.05504",
  "author_total": 4,
  "authors": [
    {
      "name": "Yuting Wang"
    },
    {
      "name": "Ruiyang Zhao"
    },
    {
      "name": "Gong-Bo Zhao"
    },
    {
      "name": "Kazuya Koyama"
    }
  ],
  "bibtex": "https://research.draconitic.com/paper/cetfy7sn1jhcd.bib",
  "cited_by": 0,
  "doi": "10.48550/arxiv.2608.05504",
  "fulltext_url": null,
  "id": "cetfy7sn1jhcd",
  "issns": [],
  "landing_url": "https://arxiv.org/abs/2608.05504",
  "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",
      "3103|Cosmology and Gravitation Theories"
    ]
  ],
  "openalex": "W7201861928",
  "pdf_url": "https://arxiv.org/pdf/2608.05504",
  "pmcid": null,
  "pmid": null,
  "published": "2026-09-21",
  "publisher": null,
  "ris": "https://research.draconitic.com/paper/cetfy7sn1jhcd.ris",
  "sources": [
    {
      "first_seen": "2026-10-30T12:23:19Z",
      "native_id": "2608.05504",
      "source": "arxiv",
      "url": "https://arxiv.org/abs/2608.05504"
    }
  ],
  "subjects": [
    {
      "field": "astronomy",
      "origin": "arxiv:astro-ph.CO",
      "subfield": "cosmology"
    }
  ],
  "title": "A Gaussian Covariance Matrix for Joint Pre- and Post-Reconstruction Full-Shape Power Spectrum Analysis",
  "title_text": "A Gaussian Covariance Matrix for Joint Pre- and Post-Reconstruction Full-Shape Power Spectrum Analysis",
  "type": "preprint",
  "updated_at": "2026-10-30T12:23:19Z",
  "url": "https://research.draconitic.com/paper/cetfy7sn1jhcd",
  "venue": "arXiv",
  "versions": []
}