{
  "abstract": "We investigate the thermodynamic and topological phase structure of charged AdS black holes with a nonminimal gauge--curvature coupling in the grand canonical ensemble. In the minimal-coupling limit $ε=0$, the system exhibits only Hawking--Page-like behavior and does not possess van der Waals criticality. Working perturbatively in the nonminimal coupling, we find that the $ε\\neq0$ interaction generates a rich phase structure as the electric potential is varied, including several distinct regimes of critical behavior, a double-critical region, and a regime where conventional criticality disappears. We complement the conventional thermodynamic analysis with a topological description based on the winding number of the thermodynamic vector field. The resulting $r_h$--$τ$ diagrams reveal that the ordering and morphology of the black-hole branches depend sensitively on both the pressure and the off-shell inverse temperature, with monotonic, disconnected, S-shaped, and cusp-like structures appearing in different parameter ranges. Remarkably, these substantial rearrangements of the solution branches can occur without changing the global winding number. In particular, the system remains in the $W=+1$ topological class beyond the range of conventional criticality, before eventually entering a $W=0$ sector. Our results demonstrate that thermodynamic topology provides complementary global information that is not captured by conventional local criticality criteria alone.",
  "abstract_shown": true,
  "affiliations": [],
  "article_type": null,
  "arxiv": "2609.13104",
  "author_total": 2,
  "authors": [
    {
      "name": "Faramarz Rahmani"
    },
    {
      "name": "Mehdi Sadeghi"
    }
  ],
  "bibtex": "https://research.draconitic.com/paper/5x7xv1cnfe90t.bib",
  "cited_by": 0,
  "doi": "10.48550/arxiv.2609.13104",
  "fulltext_url": null,
  "id": "5x7xv1cnfe90t",
  "issns": [],
  "landing_url": "https://arxiv.org/abs/2609.13104",
  "language": null,
  "licence": "CC-BY-NC-SA-4.0",
  "licence_label": "CC BY-NC-SA 4.0",
  "licence_source": "article",
  "licence_url": "http://creativecommons.org/licenses/by-nc-sa/4.0/",
  "metadata_licence": "CC0-1.0",
  "native_subjects": [
    [
      "arxiv",
      "hep-th"
    ],
    [
      "openalex",
      "3106|Black Holes and Theoretical Physics"
    ]
  ],
  "openalex": "W7212963910",
  "pdf_url": "https://arxiv.org/pdf/2609.13104",
  "pmcid": null,
  "pmid": null,
  "published": "2026-09-14",
  "publisher": null,
  "ris": "https://research.draconitic.com/paper/5x7xv1cnfe90t.ris",
  "sources": [
    {
      "first_seen": "2026-10-30T12:21:41Z",
      "native_id": "2609.13104",
      "source": "arxiv",
      "url": "https://arxiv.org/abs/2609.13104"
    }
  ],
  "subjects": [
    {
      "field": "physics",
      "origin": "arxiv:hep-th",
      "subfield": "high-energy"
    }
  ],
  "title": "Thermodynamic topology of AdS black holes with $F^{αβ}F^{γλ}R_{αγ}R_{βλ}$ coupling in the grand canonical ensemble",
  "title_text": "Thermodynamic topology of AdS black holes with F^αβF^γλR_αγR_βλ coupling in the grand canonical ensemble",
  "type": "preprint",
  "updated_at": "2026-10-30T12:21:41Z",
  "url": "https://research.draconitic.com/paper/5x7xv1cnfe90t",
  "venue": "arXiv",
  "versions": []
}