{
  "abstract": "Suppose that $f : M \\rightarrow B$ is a normal $(q-1)$-smoothing of a $2q$-manifold $M$ over some $(B,ξ)$, where $q$ is even and $B$ is simply-connected. A diffeomorphism of $M$ over $B$ induces an automorphism of the extended intersection form (or ``Q-form\") of $f$, which consists of the intersection form of $M$ and the induced homomorphism $H_q(f)$. Assuming that $H_q(B)$ is free, we determine precisely which automorphisms can be realised by such diffeomorphisms. In particular, if $H_{q-1}(B)$ is also free, then we show that every automorphism can be realised. These results are obtained by studying a ``two-sided\" version of the extended surgery obstruction, which was introduced in earlier work of the author. As an application, we show that for a complex $q$-dimensional complete intersection, with $q > 2$ even, every automorphism of the cohomology ring is realised by a diffeomorphism.",
  "abstract_shown": true,
  "affiliations": [],
  "article_type": null,
  "arxiv": "2608.24617",
  "author_total": 1,
  "authors": [
    {
      "name": "Csaba Nagy"
    }
  ],
  "bibtex": "https://research.draconitic.com/paper/4m6dawy0hph7e.bib",
  "cited_by": 0,
  "doi": "10.48550/arxiv.2608.24617",
  "fulltext_url": null,
  "id": "4m6dawy0hph7e",
  "issns": [],
  "landing_url": "https://arxiv.org/abs/2608.24617",
  "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",
      "math.GT"
    ],
    [
      "openalex",
      "2608|Geometric and Algebraic Topology"
    ]
  ],
  "openalex": "W7204252507",
  "pdf_url": "https://arxiv.org/pdf/2608.24617",
  "pmcid": null,
  "pmid": null,
  "published": "2026-08-25",
  "publisher": null,
  "ris": "https://research.draconitic.com/paper/4m6dawy0hph7e.ris",
  "sources": [
    {
      "first_seen": "2026-10-30T12:26:07Z",
      "native_id": "2608.24617",
      "source": "arxiv",
      "url": "https://arxiv.org/abs/2608.24617"
    }
  ],
  "subjects": [
    {
      "field": "mathematics",
      "origin": "arxiv:math.GT",
      "subfield": "geometry-topology"
    }
  ],
  "title": "Realising automorphisms of the extended intersection form by diffeomorphisms",
  "title_text": "Realising automorphisms of the extended intersection form by diffeomorphisms",
  "type": "preprint",
  "updated_at": "2026-10-30T12:26:07Z",
  "url": "https://research.draconitic.com/paper/4m6dawy0hph7e",
  "venue": "arXiv",
  "versions": []
}