{
  "abstract": "The Lyman-$α$ (Ly$α$) forest flux power spectrum $P(k)$ is sensitive to a range of astrophysical and cosmological effects, including the thermal state of and large-scale fluctuations in the intergalactic medium and the nature of dark matter. Measuring $P(k)$ becomes increasingly challenging at high redshift, where fewer quasar spectra are available and higher Ly$α$ optical depths result in lower transmitted flux. In addition, observational effects and missing data complicate standard Fourier-transform estimators. Here, we validate a likelihood-based estimator for $P(k)$. The method constructs the pixel-level covariance matrix of the transmitted flux field using precomputed $k$-space integrals that account for instrumental resolution and pixelization, enabling direct maximum-likelihood inference of $P(k)$. We test the estimator using mock Ly$α$ forest spectra at $z \\geq 5$, including analytic Gaussian realizations generated from known power spectra and forward-modeled simulation spectra incorporating observational effects relevant to high-redshift quasar surveys, such as finite spectral resolution, pixel sampling, noise, and missing data. We compare the recovered power spectra with both the input spectra and standard Fourier-transform estimates. We find that the likelihood-based estimator recovers the input power spectrum across the tested scales well within expected error and remains robust to the observational effects considered. This work establishes a framework for measuring Ly$α$ forest clustering with a robust, nearly optimal power spectrum estimator, with particular focus on quantifying large-scale fluctuations that may arise from ultraviolet background fluctuations or the late stages of reionization.",
  "abstract_shown": true,
  "affiliations": [],
  "article_type": null,
  "arxiv": "2610.31626",
  "author_total": 4,
  "authors": [
    {
      "name": "Molly Wolfson"
    },
    {
      "name": "Joseph F. Hennawi"
    },
    {
      "name": "Frederick B. Davies"
    },
    {
      "name": "Zarija Lukić"
    }
  ],
  "bibtex": "https://research.draconitic.com/paper/fm5aj7p2q8mgx.bib",
  "cited_by": 0,
  "doi": "10.48550/arxiv.2610.31626",
  "fulltext_url": null,
  "id": "fm5aj7p2q8mgx",
  "issns": [],
  "landing_url": "https://arxiv.org/abs/2610.31626",
  "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",
      "astro-ph.GA"
    ],
    [
      "openalex",
      "3103|Galaxies: Formation, Evolution, Phenomena"
    ]
  ],
  "openalex": "W7223292745",
  "pdf_url": "https://arxiv.org/pdf/2610.31626",
  "pmcid": null,
  "pmid": null,
  "published": "2026-10-22",
  "publisher": null,
  "ris": "https://research.draconitic.com/paper/fm5aj7p2q8mgx.ris",
  "sources": [
    {
      "first_seen": "2026-10-30T12:34:34Z",
      "native_id": "2610.31626",
      "source": "arxiv",
      "url": "https://arxiv.org/abs/2610.31626"
    }
  ],
  "subjects": [
    {
      "field": "astronomy",
      "origin": "arxiv:astro-ph.CO",
      "subfield": "cosmology"
    },
    {
      "field": "astronomy",
      "origin": "arxiv:astro-ph.GA",
      "subfield": "galaxies"
    }
  ],
  "title": "A Robust Estimator for the Lyman-$α$ Forest 1D Power Spectrum at High Redshift",
  "title_text": "A Robust Estimator for the Lyman-α Forest 1D Power Spectrum at High Redshift",
  "type": "preprint",
  "updated_at": "2026-10-30T12:34:34Z",
  "url": "https://research.draconitic.com/paper/fm5aj7p2q8mgx",
  "venue": "arXiv",
  "versions": []
}