{
  "abstract": "Universal behavior at continuous phase transitions is encoded in long-wavelength fixed-point theories controlled by dimensionality and symmetries. It is a central question for which systems this universal behavior and the underlying long-wavelength description can be captured by a noninteracting theory allowing for analytical and accurate predictions. In this work we provide a systematic procedure for obtaining the best noninteracting fermionic description of a quantum phase transition through fermionic Gaussian states. We demonstrate the performance of our procedure for the interacting long-range transverse-field Ising chain. This formulation reduces the problem to a self-consistent Euler equation that yields a critical line in close agreement with independent numerical benchmarks, while its singular momentum structure provides analytic predictions for continuously varying critical properties. Yet exact diagonalization shows that Gaussian-state fidelity to the exact ground state is poorest, and non-Gaussianity strongest, near the transition. Thus, accurate predictions for critical properties can emerge from the Gaussian variational description even where its microscopic wave-function approximation is weakest.",
  "abstract_shown": true,
  "affiliations": [],
  "article_type": null,
  "arxiv": "2610.26246",
  "author_total": 4,
  "authors": [
    {
      "name": "Reyhaneh Khasseh"
    },
    {
      "name": "Fabian Ballar Trigueros"
    },
    {
      "name": "Markus Heyl"
    },
    {
      "name": "M. A. Rajabpour"
    }
  ],
  "bibtex": "https://research.draconitic.com/paper/edfh3sfrb1hmw.bib",
  "cited_by": 0,
  "doi": "10.48550/arxiv.2610.26246",
  "fulltext_url": null,
  "id": "edfh3sfrb1hmw",
  "issns": [],
  "landing_url": "https://arxiv.org/abs/2610.26246",
  "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",
      "cond-mat.stat-mech"
    ],
    [
      "arxiv",
      "quant-ph"
    ],
    [
      "openalex",
      "3107|Quantum many-body systems"
    ]
  ],
  "openalex": "W7223064378",
  "pdf_url": "https://arxiv.org/pdf/2610.26246",
  "pmcid": null,
  "pmid": null,
  "published": "2026-10-19",
  "publisher": null,
  "ris": "https://research.draconitic.com/paper/edfh3sfrb1hmw.ris",
  "sources": [
    {
      "first_seen": "2026-10-30T12:30:52Z",
      "native_id": "2610.26246",
      "source": "arxiv",
      "url": "https://arxiv.org/abs/2610.26246"
    }
  ],
  "subjects": [
    {
      "field": "physics",
      "origin": "arxiv:quant-ph",
      "subfield": "quantum"
    },
    {
      "field": "physics",
      "origin": "arxiv:cond-mat.stat-mech",
      "subfield": "statistical-nonlinear"
    }
  ],
  "title": "Universal Quantum Criticality from a Gaussian Variational Manifold",
  "title_text": "Universal Quantum Criticality from a Gaussian Variational Manifold",
  "type": "preprint",
  "updated_at": "2026-10-30T12:33:41Z",
  "url": "https://research.draconitic.com/paper/edfh3sfrb1hmw",
  "venue": "arXiv",
  "versions": []
}