Deformations of singularities and variations of GIT quotients I -- Radu Laza

In this talk we will discuss the deformations of two classes of singularities: the minimally elliptic surface singularity $N_{16}$ and the threefold singularity $O_{16}$ (the cone over a cubic surface). Via a standard procedure, due to Pinkham, the study of the deformations of $N_{16}$ is reduced to the study of a moduli space of pairs $(C,L)$ consisting of a plane quintic curve and a line. We construct this moduli space of pairs by using both Hodge theory and GIT. Each construction provides complementary information, and together they offer a complete description of the deformations of $N_ {16}$. Similar considerations apply for $O_{16}$.