{
  "abstract": "The choice of statistical ensemble has a measurable impact on the statistical description of Bose-Einstein condensates beyond the well-known grand canonical anomaly. We develop a segmented-contour approach for the ideal Bose gas, which refines the saddle-point approximation by including non-Gaussian corrections in the canonical and microcanonical ensembles. The method applies to a broad class of noninteracting spectra, and provides efficient access to condensate fluctuations, higher moments, and correlation functions. For a three-dimensional harmonic trap with fixed anisotropy, we find that the ratio of the maxima of the microcanonical and canonical condensate-number variances approaches the theoretically predicted asymptotic value $1-3ζ(3)^2/[4ζ(2)ζ(4)]\\approx 0.391$ only extremely slowly with increasing particle number. We also show that ensemble effects are visible in the second-order correlation function $g^{(2)}(x)$ near the condensation crossover. After ballistic release from a three-dimensional harmonic trap, the time evolution of $g^{(2)}(x)$ preserves the differences between statistical ensembles.",
  "abstract_shown": true,
  "affiliations": [],
  "article_type": null,
  "arxiv": "2610.36118",
  "author_total": 7,
  "authors": [
    {
      "name": "Szymon Augustynowicz"
    },
    {
      "name": "Jan Okoński"
    },
    {
      "name": "Maciej B. Kruk"
    },
    {
      "name": "Ilja Zebergs"
    },
    {
      "name": "Jan Joachim Arlt"
    },
    {
      "name": "Kazimierz Rzążewski"
    },
    {
      "name": "Krzysztof Pawłowski"
    }
  ],
  "bibtex": "https://research.draconitic.com/paper/05dgchaa95gj4.bib",
  "cited_by": 0,
  "doi": "10.48550/arxiv.2610.36118",
  "fulltext_url": null,
  "id": "05dgchaa95gj4",
  "issns": [],
  "landing_url": "https://arxiv.org/abs/2610.36118",
  "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.quant-gas"
    ],
    [
      "arxiv",
      "cond-mat.stat-mech"
    ],
    [
      "openalex",
      "3107|Cold Atom Physics and Bose-Einstein Condensates"
    ]
  ],
  "openalex": "W7224095921",
  "pdf_url": "https://arxiv.org/pdf/2610.36118",
  "pmcid": null,
  "pmid": null,
  "published": "2026-10-26",
  "publisher": null,
  "ris": "https://research.draconitic.com/paper/05dgchaa95gj4.ris",
  "sources": [
    {
      "first_seen": "2026-10-30T12:35:50Z",
      "native_id": "2610.36118",
      "source": "arxiv",
      "url": "https://arxiv.org/abs/2610.36118"
    }
  ],
  "subjects": [
    {
      "field": "physics",
      "origin": "arxiv:cond-mat.quant-gas",
      "subfield": "amo"
    },
    {
      "field": "physics",
      "origin": "arxiv:cond-mat.quant-gas",
      "subfield": "condensed-matter"
    },
    {
      "field": "physics",
      "origin": "arxiv:cond-mat.stat-mech",
      "subfield": "statistical-nonlinear"
    }
  ],
  "title": "Ensemble-dependent condensate statistics and correlations in an ideal Bose gas",
  "title_text": "Ensemble-dependent condensate statistics and correlations in an ideal Bose gas",
  "type": "preprint",
  "updated_at": "2026-10-30T12:35:50Z",
  "url": "https://research.draconitic.com/paper/05dgchaa95gj4",
  "venue": "arXiv",
  "versions": []
}