Lectures by Prof. Barbara Fantechi (SISSA) at the Research Institute for Mathematical Sciences (RIMS), Kyoto University, April 13–14, 2026.
After briefly reviewing functors over Artinian algebras (over a fixed algebraically closed field) we focus on deformations of singular varieties, and in particular those which have lci singularities.

We review Tziolas’s result on formal smoothability, describe applications to smoothening of stable surfaces (joint work with Franciosi and Pardini) and a similar, independent smoothability result (joint with Miró Roig).

We relate what done so far with algebraic stacks and complex analytic geometry; if time allows we discuss work in progress with Siao Chi Mok on the stack of Fulton-MacPherson expansions.
