{
  "abstract": "Symmetry-enforced gaplessness is a phenomenon in which a quantum system is forced to be gapless due to its global symmetry. Previous works have mainly focused on anomalous symmetries. Another approach, using symmetry spans, which specify two embeddings of a common symmetry into two larger symmetries, was proposed by the authors. In this work, we show that a symmetry span can enforce gaplessness even when both larger symmetries are invertible and non-anomalous: each alone admits a trivially gapped phase, but because the embeddings differ by a twist associated with a symmetry-protected topological phase, the symmetry they generate admits no gapped phase with finitely many ground states. We present such a span of a finite group and $\\mathrm{U}(1)^2$ in 1+1 dimensions, with continuum realizations and a lattice Hamiltonian, with a finite-dimensional local Hilbert space and finitely many parameters, that is gapless in any region of its parameter space. We also discuss a 2+1-dimensional example and spans of only finite symmetries.",
  "abstract_shown": true,
  "affiliations": [],
  "article_type": null,
  "arxiv": "2611.03164",
  "author_total": 2,
  "authors": [
    {
      "name": "Takamasa Ando"
    },
    {
      "name": "Kantaro Ohmori"
    }
  ],
  "bibtex": "https://research.draconitic.com/paper/drpmz5atakpsj.bib",
  "cited_by": 0,
  "doi": "10.48550/arxiv.2611.03164",
  "fulltext_url": null,
  "id": "drpmz5atakpsj",
  "issns": [],
  "landing_url": "https://arxiv.org/abs/2611.03164",
  "language": null,
  "licence": "CC-BY-4.0",
  "licence_label": "CC BY 4.0",
  "licence_source": "article",
  "licence_url": "http://creativecommons.org/licenses/by/4.0/",
  "metadata_licence": "CC0-1.0",
  "native_subjects": [
    [
      "arxiv",
      "cond-mat.str-el"
    ],
    [
      "arxiv",
      "hep-th"
    ],
    [
      "arxiv",
      "math-ph"
    ],
    [
      "arxiv",
      "math.MP"
    ]
  ],
  "openalex": null,
  "pdf_url": "https://arxiv.org/pdf/2611.03164",
  "pmcid": null,
  "pmid": null,
  "published": "2026-11-02",
  "publisher": null,
  "ris": "https://research.draconitic.com/paper/drpmz5atakpsj.ris",
  "sources": [
    {
      "first_seen": "2026-11-03T12:21:04Z",
      "native_id": "2611.03164",
      "source": "arxiv",
      "url": "https://arxiv.org/abs/2611.03164"
    }
  ],
  "subjects": [
    {
      "field": "mathematics",
      "origin": "arxiv:math-ph",
      "subfield": "mathematical-physics"
    },
    {
      "field": "physics",
      "origin": "arxiv:cond-mat.str-el",
      "subfield": "condensed-matter"
    },
    {
      "field": "physics",
      "origin": "arxiv:hep-th",
      "subfield": "high-energy"
    }
  ],
  "title": "Enforced Gaplessness by Combining Non-Anomalous Symmetries",
  "title_text": "Enforced Gaplessness by Combining Non-Anomalous Symmetries",
  "type": "preprint",
  "updated_at": "2026-11-05T15:20:28Z",
  "url": "https://research.draconitic.com/paper/drpmz5atakpsj",
  "venue": "arXiv",
  "versions": []
}