English

On an example of Aspinwall, Morrison, and Szendr\H{o}i

Algebraic Geometry 2024-07-30 v2

Abstract

We study the cohomology of a 1-parameter family Y_t of Calabi-Yau 3-folds introduced by Aspinwall and Morrison, related to the mirror quintic family. Szendr\H{o}i proved that Y_t, Y_{xi t}, ..., Y_{xi^4 t}, where xi is a fifth root of unity, have the same rational Hodge structure but are not isomorphic, and conjectured that they are not birational or even derived equivalent. We confirm this by proving that their integral Hodge structures are different, and discuss how this fits with known Torelli-type theorems and counterexamples.

Keywords

Cite

@article{arxiv.2407.11176,
  title  = {On an example of Aspinwall, Morrison, and Szendr\H{o}i},
  author = {Nicolas Addington and Benjamin Tighe},
  journal= {arXiv preprint arXiv:2407.11176},
  year   = {2024}
}

Comments

26 pages. v2: submitted version. second theorem turns out to be known; added references but kept our self-contained proof