{
  "abstract": "A bstract : Motivated by the observation that 2 + 2 = 4, we consider four-dimensional $$ \\mathcal{N} $$ N = 2 superconformal field theories on S ² × Σ, turning on a suitable rigid supergravity background. On the one hand, reduction of a four-dimensional theory T on a Riemann surface Σ leads to a family $$ \\mathcal{F}\\left[T,\\Sigma \\right] $$ F T Σ of two-dimensional (2, 2) unitary SCFTs, a two-dimensional analog of the four-dimensional theories of class $$ \\mathcal{S} $$ S . On the other hand, reduction on S ² yields a non-unitary two-dimensional CFT $$ \\mathcal{C}\\left[T\\right] $$ C T whose chiral algebra is the same as the one associated to T by the standard SCFT/VOA correspondence. This construction upgrades the vertex operator algebra to a full-fledged two-dimensional CFT. What’s more, it leads to a novel 2d/2d correspondence, a “2 + 2 = 4” analog of the “4 + 2 = 6” AGT correspondence: the S ² partition function of $$ \\mathcal{F}\\left[T;\\Sigma \\right] $$ F T Σ is computed by correlation functions of $$ \\mathcal{C}\\left[T\\right] $$ C T on Σ. The elliptic genus of $$ \\mathcal{F}\\left[T;\\Sigma \\right] $$ F T Σ is instead computed by a topological QFT $$ \\mathcal{E}\\left[T\\right] $$ E T on Σ. A central question is whether one can give a purely two-dimensional presentation of the family $$ \\mathcal{F}\\left[T;\\Sigma \\right] $$ F T Σ of (2, 2) theories. We propose an algorithm to realize the (2, 2) theories as gauged linear sigma models when T is an Argyres-Douglas theory of type ( A ₁ , A 2 k ) and Σ an n -punctured sphere. We perform stringent checks of our conjecture for k = 1 and k = 2.",
  "abstract_shown": true,
  "affiliations": [
    "Stony Brook University",
    "School of Natural Sciences, Institute for Advanced Study",
    "University of Haifa at Oranim",
    "University of Haifa"
  ],
  "article_type": null,
  "arxiv": null,
  "author_total": 4,
  "authors": [
    {
      "affs": [
        0
      ],
      "name": "Leonardo Rastelli",
      "orcid": "0000-0001-9587-3936"
    },
    {
      "affs": [
        1
      ],
      "name": "Brandon C. Rayhaun",
      "orcid": "0000-0002-7242-4481"
    },
    {
      "affs": [
        0
      ],
      "name": "Matteo Sacchi",
      "orcid": "0000-0003-0316-3369"
    },
    {
      "affs": [
        2,
        3
      ],
      "name": "Gabi Zafrir",
      "orcid": "0000-0003-2609-5290"
    }
  ],
  "bibtex": "https://research.draconitic.com/paper/71j8krg2b66hp.bib",
  "cited_by": 0,
  "doi": "10.1007/jhep09(2026)242",
  "fulltext_url": null,
  "id": "71j8krg2b66hp",
  "issns": [
    "1029-8479"
  ],
  "landing_url": "https://link.springer.com/10.1007/JHEP09(2026)242",
  "language": null,
  "licence": "CC-BY-4.0",
  "licence_label": "CC BY 4.0",
  "licence_source": "article",
  "licence_url": "https://creativecommons.org/licenses/by/4.0",
  "metadata_licence": null,
  "native_subjects": [
    [
      "openalex",
      "3106|Black Holes and Theoretical Physics"
    ]
  ],
  "openalex": "W7214918677",
  "pdf_url": "https://link.springer.com/content/pdf/10.1007/JHEP09(2026)242.pdf",
  "pmcid": null,
  "pmid": null,
  "published": "2026-09-23",
  "publisher": "Springer Science and Business Media LLC",
  "ris": "https://research.draconitic.com/paper/71j8krg2b66hp.ris",
  "sources": [
    {
      "first_seen": "2026-10-30T12:18:01Z",
      "native_id": "10.1007/jhep09(2026)242",
      "source": "crossref",
      "url": "https://link.springer.com/10.1007/JHEP09(2026)242"
    }
  ],
  "subjects": [
    {
      "field": "physics",
      "origin": "openalex:3106|Black Holes and Theoretical Physics",
      "subfield": "high-energy"
    }
  ],
  "title": "2 + 2 = 4 a 2d/2d unitary/non-unitary correspondence",
  "title_text": "2 + 2 = 4 a 2d/2d unitary/non-unitary correspondence",
  "type": "peer-reviewed",
  "updated_at": "2026-10-30T12:18:01Z",
  "url": "https://research.draconitic.com/paper/71j8krg2b66hp",
  "venue": "Journal of High Energy Physics",
  "versions": []
}