2023/10/16 by Colombo, Elisabetta, Frediani, Paola, Naranjo, Juan Carlos +1
#Algebraic Geometry (math.AG) #FOS: Mathematics
paper · doi:10.48550/arxiv.2310.10398
We study the local geometry of the moduli space of intermediate Jacobians of (2,2)-threefolds in \mathbb P2 × \mathbb P2. More precisely, we prove that a composition of the second fundamental form of the Siegel metric in \mathcal A9 restricted to this moduli space, with a natural multiplication map is a nonzero holomorphic section of a vector bundle. We also describe its kernel. We use the two conic bundle structures of these threefolds, Prym theory, gaussian maps and Jacobian ideals.