{
  "annotation_id": "6b43b269-16c5-483a-a02a-ae4642e470cb",
  "date_created": "2026-03-02T18:01:39.152000Z",
  "date_modified": "2026-03-02T18:01:39.152000Z",
  "file_hash": "8df70e97586fa852bd85281aead252b97564667b0f3553251cc06b90f15fea41",
  "private": false,
  "record": {
    "abstract": "In this paper, a variational perturbation scheme for nonrelativistic\nmany-Fermion systems is generalized to a Bosonic system. By calculating the\nfree energy of an anharmonic oscillator model, we investigated this variational\nexpansion scheme for its efficiency. Using the modified Feynman rules for the\ndiagrams, we obtained the analytical expression of the free energy up to the\nfourth order. Our numerical results at various orders are compared with the\nexact and other relevant results.",
    "arxiv_id": "quant-ph/0009017",
    "authors": [
      "Wen-Fa Lu",
      "Sang Koo You",
      "Jino Bak",
      "Chul Koo Kim",
      "Kyun Nahm"
    ],
    "categories": [
      "quant-ph"
    ],
    "doi": "10.1088/0305-4470/35/1/302",
    "journal_ref": "J. Phys. A 35, (2002) 21",
    "title": "A Variational Expansion for the Free Energy of a Bosonic System",
    "url": "https://arxiv.org/abs/quant-ph/0009017"
  },
  "schema_id": "dorsal/arxiv",
  "source": {
    "execution_id": "db51245d-3980-48b6-8330-53b8c72a8311",
    "id": "arXiv Dataset IDs",
    "type": "Model",
    "variant": "snapshot-2026-03-01",
    "version": "0.1.0"
  },
  "user_id": 1000002
}