{
  "abstract": "Contemporary large-scale structure analyses center around the galaxy power spectrum, modeled with one-loop perturbation theory. This description naturally breaks down at large wavenumbers, prohibiting the extraction of cosmological information from small-scale clustering. In this work, we present a complete model for the redshift-space galaxy power spectrum up to two-loop order, derived in the framework of the Effective Field Theory of Large Scale Structure. This accounts for a wide variety of effects, including fifth-order galaxy bias, redshift-space distortions, small-scale non-linearities, spatial non-locality, bulk flows, coordinate distortions, and stochasticity, involving 49 free coefficients. Our model additionally encodes all deterministic and counterterm contributions to the one-loop bispectrum and trispectrum (as well as the tree-level quadspectrum and pentaspectrum), which depend on many of the same parameters. We implement the model numerically, using the VEGAS algorithm to precompute the loop integrals; this allows the full likelihood to be evaluated in milliseconds. The approach is validated using power spectra measured from high-resolution simulations, considering both dark matter and realistic galaxy samples. The extension to two-loop order greatly increases the range of scales over which the power spectrum can be modeled, with $k_{\\rm max}$ rising from $0.20h\\,\\mathrm{Mpc}^{-1}$ to $0.34h\\,\\mathrm{Mpc}^{-1}$ for a luminous red galaxy sample at $z=0.5$, or $0.27h\\,\\mathrm{Mpc}^{-1}$ to $0.42h\\,\\mathrm{Mpc}^{-1}$ for an emission line galaxy sample at $z=1.1$. Much of the additional information is absorbed by the numerous fifth-order biases and counterterms; for this reason, constraints on $σ_8$ are not significantly enhanced by the inclusion of two-loop terms. Future work will assess the implications of the two-loop model for cosmological parameter inference.",
  "abstract_shown": true,
  "affiliations": [],
  "article_type": null,
  "arxiv": "2610.13867",
  "author_total": 1,
  "authors": [
    {
      "name": "Oliver H. E. Philcox"
    }
  ],
  "bibtex": "https://research.draconitic.com/paper/cdqz6rnpkkcxq.bib",
  "cited_by": 0,
  "doi": "10.48550/arxiv.2610.13867",
  "fulltext_url": null,
  "id": "cdqz6rnpkkcxq",
  "issns": [],
  "landing_url": "https://arxiv.org/abs/2610.13867",
  "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-ex"
    ],
    [
      "arxiv",
      "hep-ph"
    ],
    [
      "arxiv",
      "hep-th"
    ],
    [
      "openalex",
      "3103|Cosmology and Gravitation Theories"
    ]
  ],
  "openalex": "W7221552566",
  "pdf_url": "https://arxiv.org/pdf/2610.13867",
  "pmcid": null,
  "pmid": null,
  "published": "2026-10-25",
  "publisher": null,
  "ris": "https://research.draconitic.com/paper/cdqz6rnpkkcxq.ris",
  "sources": [
    {
      "first_seen": "2026-10-30T12:35:35Z",
      "native_id": "2610.13867",
      "source": "arxiv",
      "url": "https://arxiv.org/abs/2610.13867"
    }
  ],
  "subjects": [
    {
      "field": "astronomy",
      "origin": "arxiv:astro-ph.CO",
      "subfield": "cosmology"
    },
    {
      "field": "physics",
      "origin": "arxiv:gr-qc",
      "subfield": "gravitation"
    },
    {
      "field": "physics",
      "origin": "arxiv:hep-ex",
      "subfield": "high-energy"
    }
  ],
  "title": "The Redshift-Space Galaxy Power Spectrum at Two-Loop Order",
  "title_text": "The Redshift-Space Galaxy Power Spectrum at Two-Loop Order",
  "type": "preprint",
  "updated_at": "2026-10-30T12:35:35Z",
  "url": "https://research.draconitic.com/paper/cdqz6rnpkkcxq",
  "venue": "arXiv",
  "versions": []
}