{
  "id": "2108.01587",
  "version": "v1",
  "published": "2021-08-03T15:51:09.000Z",
  "updated": "2021-08-03T15:51:09.000Z",
  "title": "On type II degenerations of hyperkähler manifolds",
  "authors": [
    "Daniel Huybrechts",
    "Mirko Mauri"
  ],
  "comment": "12 pages. Comments are welcome!",
  "categories": [
    "math.AG"
  ],
  "abstract": "We give a simple argument to prove Nagai's conjecture for type II degenerations of compact hyperk\\\"ahler manifolds and cohomology classes of middle degree. Under an additional assumption, the techniques yield the conjecture in arbitrary degree. This would complete the proof of Nagai's conjecture in general, as it was proved already for type I degenerations by Koll\\'ar, Laza, Sacc\\`a, and Voisin and independently by Soldatenkov, while it is immediate for type III degenerations. Our arguments are close in spirit to a recent paper by Harder proving similar results for the restrictive class of good degenerations.",
  "revisions": [
    {
      "version": "v1",
      "updated": "2021-08-03T15:51:09.000Z"
    }
  ],
  "analyses": {
    "subjects": [
      "14J42",
      "14D06"
    ],
    "keywords": [
      "hyperkähler manifolds",
      "degenerations",
      "nagais conjecture",
      "harder proving similar results",
      "simple argument"
    ],
    "note": {
      "typesetting": "TeX",
      "pages": 12,
      "language": "en",
      "license": "arXiv",
      "status": "editable"
    }
  }
}