Moduli Spaces of Polarized Symplectic O'Grady Varieties and Borcherds Products

Abstract

We study moduli spaces of O'Grady’s ten-dimensional irreducible symplectic manifolds. These moduli spaces are covers of modular varieties of dimension 21, namely quotients of hermitian symmetric domains by a suitable arithmetic group. The interesting and new aspect of this case is that the group in question is strictly bigger than the stable orthogonal group. This makes it different from both the K3 and the $K3^{[n]}$ case, which are of dimension 19 and 20 respectively.