{
  "abstract": "The in-medium similarity renormalization group (IMSRG) is a leading \\textit{ab initio} method for describing atomic nuclei. Most applications truncate the flowing operators at the normal-ordered two-body level, neglecting induced higher-body terms. Convergence with increasing operator rank remains poorly understood, particularly in strongly correlated systems. We systematically assess the many-body truncation hierarchy in the single-reference and multi-reference IMSRG, retaining normal-ordered operators through the four-body and three-body levels, respectively. Using an exactly solvable pairing-plus-particle-hole model, we quantify successive higher-body corrections over a broad range of interaction strengths, spanning weakly to strongly correlated regimes. The multi-reference formulation exhibits faster and more robust convergence than its single-reference counterpart, with the advantage becoming most pronounced at strong coupling. In this regime, higher-rank irreducible density matrices play an essential role in achieving convergence of the many-body expansion.",
  "abstract_shown": true,
  "affiliations": [],
  "article_type": null,
  "arxiv": "2611.01458",
  "author_total": 3,
  "authors": [
    {
      "name": "L. H. Chen"
    },
    {
      "name": "H. Hergert"
    },
    {
      "name": "J. M. Yao"
    }
  ],
  "bibtex": "https://research.draconitic.com/paper/bq0sk1atqdjwp.bib",
  "cited_by": 0,
  "doi": "10.48550/arxiv.2611.01458",
  "fulltext_url": null,
  "id": "bq0sk1atqdjwp",
  "issns": [],
  "landing_url": "https://arxiv.org/abs/2611.01458",
  "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",
      "cond-mat.str-el"
    ],
    [
      "arxiv",
      "nucl-ex"
    ],
    [
      "arxiv",
      "nucl-th"
    ]
  ],
  "openalex": null,
  "pdf_url": "https://arxiv.org/pdf/2611.01458",
  "pmcid": null,
  "pmid": null,
  "published": "2026-11-01",
  "publisher": null,
  "ris": "https://research.draconitic.com/paper/bq0sk1atqdjwp.ris",
  "sources": [
    {
      "first_seen": "2026-11-03T12:20:59Z",
      "native_id": "2611.01458",
      "source": "arxiv",
      "url": "https://arxiv.org/abs/2611.01458"
    }
  ],
  "subjects": [
    {
      "field": "physics",
      "origin": "arxiv:cond-mat.str-el",
      "subfield": "condensed-matter"
    },
    {
      "field": "physics",
      "origin": "arxiv:nucl-ex",
      "subfield": "nuclear"
    }
  ],
  "title": "Convergence of many-body truncations in the in-medium similarity renormalization group",
  "title_text": "Convergence of many-body truncations in the in-medium similarity renormalization group",
  "type": "preprint",
  "updated_at": "2026-11-05T15:20:18Z",
  "url": "https://research.draconitic.com/paper/bq0sk1atqdjwp",
  "venue": "arXiv",
  "versions": []
}