On the period of Lehn, Lehn, Sorger, and van Straten's symplectic eightfold
arXiv:2003.10984 · doi:10.1215/21562261-2022-0033
Abstract
For the irreducible holomorphic symplectic eightfold Z associated to a cubic fourfold Y not containing a plane, we show that a natural Abel-Jacobi map from H^4_prim(Y) to H^2_prim(Z) is a Hodge isometry. We describe the full H^2(Z) in terms of the Mukai lattice of the K3 category A of Y. We give numerical conditions for Z to be birational to a moduli space of sheaves on a K3 surface or to Hilb^4(K3). We propose a conjecture on how to use Z to produce equivalences from A to the derived category of a K3 surface.
18 pages, Macaulay2 code as ancillary file. v3: final version to appear in Kyoto J. Math