English

Reduced Tate-Shafarevich group

Algebraic Geometry 2024-05-07 v3

Abstract

We prove a sort of reconstruction theorem for generic elliptic Calabi-Yau 33-folds in the sense of C\u{a}ld\u{a}raru. From our argument it follows that two generic elliptic Calabi-Yau 33-folds are derived-equivalent linear over the base if and only if their generic fibers are derived-equivalent. As an application, we give affirmative answers to the conjectures raised by Knapp-Scheidegger-Schimannek. Namely, for each pair of elliptic Calabi-Yau 33-folds in their list we prove that they share the relative Jacobian and are P2P^2-linear derived-equivalent.

Keywords

Cite

@article{arxiv.2205.11268,
  title  = {Reduced Tate-Shafarevich group},
  author = {Hayato Morimura},
  journal= {arXiv preprint arXiv:2205.11268},
  year   = {2024}
}

Comments

22 pages; v3: Removed results about nonbirationality and computation of Tate--Shafarevich group. Modified a statement and the proofs in the subsection Calabi--Yau case. Added sections corresponding to arXiv:2301.12751v4 after some modifications

R2 v1 2026-06-24T11:25:36.628Z