{
  "abstract": "We study the spectral gap $Δ_1$ of Narain CFTs, the smallest scaling dimension of a nonvacuum $U(1)^c_L\\times U(1)^c_R$ primary, as a function on the Narain moduli space. Using the exceptional isomorphisms for $SO^+(2,2)$ and $SO^+(3,3)$, we prove the sharp bounds $Δ_1\\le 2/3$ at $c=2$ and $Δ_1\\le 3/4$ at $c=3$, with equality exactly at the $SU(3)_1$ and $SU(4)_1$ WZW models up to $O(c)\\times O(c)$, and we describe local maxima of $Δ_1$. For $4\\le c\\le 12$, we compare the Narain moduli space with the densest known Euclidean lattices: an arithmetic obstruction excludes five candidates, a computer-assisted classification shows that $E_8$, $K_{12}$, and $BW_{16}$ each admit a unique Narain structure up to lattice automorphisms, and a conceptual argument excludes the Leech lattice.",
  "abstract_shown": true,
  "affiliations": [],
  "article_type": null,
  "arxiv": "2610.22633",
  "author_total": 2,
  "authors": [
    {
      "name": "Hyeongjoe Chu"
    },
    {
      "name": "Yuchan Jung"
    }
  ],
  "bibtex": "https://research.draconitic.com/paper/904j0byh6bnq0.bib",
  "cited_by": 0,
  "doi": "10.48550/arxiv.2610.22633",
  "fulltext_url": null,
  "id": "904j0byh6bnq0",
  "issns": [],
  "landing_url": "https://arxiv.org/abs/2610.22633",
  "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",
      "hep-th"
    ],
    [
      "arxiv",
      "math.MG"
    ],
    [
      "openalex",
      "2608|Algebraic structures and combinatorial models"
    ]
  ],
  "openalex": "W7222928168",
  "pdf_url": "https://arxiv.org/pdf/2610.22633",
  "pmcid": null,
  "pmid": null,
  "published": "2026-10-15",
  "publisher": null,
  "ris": "https://research.draconitic.com/paper/904j0byh6bnq0.ris",
  "sources": [
    {
      "first_seen": "2026-10-30T12:30:32Z",
      "native_id": "2610.22633",
      "source": "arxiv",
      "url": "https://arxiv.org/abs/2610.22633"
    }
  ],
  "subjects": [
    {
      "field": "mathematics",
      "origin": "arxiv:math.MG",
      "subfield": "geometry-topology"
    },
    {
      "field": "physics",
      "origin": "arxiv:hep-th",
      "subfield": "high-energy"
    }
  ],
  "title": "Maximizing the spectral gap for free bosonic CFTs",
  "title_text": "Maximizing the spectral gap for free bosonic CFTs",
  "type": "preprint",
  "updated_at": "2026-10-30T12:33:31Z",
  "url": "https://research.draconitic.com/paper/904j0byh6bnq0",
  "venue": "arXiv",
  "versions": []
}