English

Dual double EPW-sextics and their periods

Algebraic Geometry 2007-05-23 v1

Abstract

A locally complete family of projective symplectic 4-folds is provided by natural double covers of Eisenbud-Popescu-Walter (EPW) sextic hypersurfaces in projective 5-space. The dual of an EPW sextic is another EPW sextic, thus to a double EPW sextic X we may associate a "dual" double EPW sextic X^{\vee}. We show how to obtain the Hodge structure on H^2(X^{\vee}) from that on H^2(X); it turns out that they are isomorphic over the rationals but not over the integers (in general).

Cite

@article{arxiv.math/0605085,
  title  = {Dual double EPW-sextics and their periods},
  author = {Kieran G. O'Grady},
  journal= {arXiv preprint arXiv:math/0605085},
  year   = {2007}
}

Comments

31 pages

R2 v1 2026-07-22T17:35:18.265Z