{
  "abstract": "In this work, we develop two many-body quantum electrodynamic methods to calculate the ground-state energies of strongly coupled light-matter molecular systems. Specifically, we extend the second-order many-body Green's function theory (GF2) for electronic systems to incorporate electron-boson couplings. We employ two ansätze to treat the bosonic part of the system, namely the coherent-state (CS) and Lang-Firsov (LF) transformed vacuum state. These are combined with the GF2 method to construct two new approaches, which we refer to as CS-GF2 and LF-GF2. We benchmark CS- and LF-GF2 by studying various molecular systems inside an optical cavity. We investigate $\\mathrm{H}_2$ and $\\mathrm{LiH}$ potential energy surfaces, keto-enol tautomerization energy barrier, van der Waals interactions between two $\\mathrm{H_2}$ molecules and the torsional potential energy surface of the ethylene molecule, $\\mathrm{C_2H_4}$. Both methods provide similar energy profiles, with relatively small differences between CS-GF2 and LF-GF2. Comparisons with the reference calculations also reveal remaining limitations at stretched bond lengths and near the twisted ethylene configuration. We additionally benchmark CS-GF2 against exact diagonalization for a two-site Hubbard-Holstein model and observe that it closely reproduces the coupling-induced energy change in the weakly interacting regime while improving upon CS-MP2 in the strongly interacting regime. Overall, the results demonstrate that CS-GF2 and LF-GF2 provide self-consistent descriptions of correlated molecular electron-boson systems, offering a many-body Green's function alternative for studying ground-state cavity-modified systems.",
  "abstract_shown": true,
  "affiliations": [],
  "article_type": null,
  "arxiv": "2606.26076",
  "author_total": 4,
  "authors": [
    {
      "name": "Amirhosein Amini"
    },
    {
      "name": "Jaime Cerda"
    },
    {
      "name": "Leopoldo Mejía"
    },
    {
      "name": "Arkajit Mandal"
    }
  ],
  "bibtex": "https://research.draconitic.com/paper/169zcmmv6ca52.bib",
  "cited_by": 0,
  "doi": "10.48550/arxiv.2606.26076",
  "fulltext_url": null,
  "id": "169zcmmv6ca52",
  "issns": [],
  "landing_url": "https://arxiv.org/abs/2606.26076",
  "language": null,
  "licence": "CC-BY-NC-ND-4.0",
  "licence_label": "CC BY-NC-ND 4.0",
  "licence_source": "article",
  "licence_url": "http://creativecommons.org/licenses/by-nc-nd/4.0/",
  "metadata_licence": "CC0-1.0",
  "native_subjects": [
    [
      "arxiv",
      "cond-mat.str-el"
    ],
    [
      "arxiv",
      "quant-ph"
    ]
  ],
  "openalex": null,
  "pdf_url": "https://arxiv.org/pdf/2606.26076",
  "pmcid": null,
  "pmid": null,
  "published": "2026-09-23",
  "publisher": null,
  "ris": "https://research.draconitic.com/paper/169zcmmv6ca52.ris",
  "sources": [
    {
      "first_seen": "2026-10-30T12:24:11Z",
      "native_id": "2606.26076",
      "source": "arxiv",
      "url": "https://arxiv.org/abs/2606.26076"
    }
  ],
  "subjects": [
    {
      "field": "physics",
      "origin": "arxiv:cond-mat.str-el",
      "subfield": "condensed-matter"
    },
    {
      "field": "physics",
      "origin": "arxiv:quant-ph",
      "subfield": "quantum"
    }
  ],
  "title": "Many-Body Second Order Green's Function Theory for Ab Initio Molecular Quantum Electrodynamics",
  "title_text": "Many-Body Second Order Green's Function Theory for Ab Initio Molecular Quantum Electrodynamics",
  "type": "preprint",
  "updated_at": "2026-10-30T12:24:11Z",
  "url": "https://research.draconitic.com/paper/169zcmmv6ca52",
  "venue": "arXiv",
  "versions": []
}