Hirokazu Nasu (Tokai University): Obstructions to deforming curves on an Enriques-Fano 3-fold

Abstract: An Enriques-Fano 3-fold (called EF3, for short) is a 3-dimensional projective variety having a hyperplane section that is a smooth Enriques surface.  We discuss the deformations of curves on an EF3 assuming that they are contained in a smooth hyperplane section (an Enriques surface). We also discuss the existence of a generically non-reduced component of the Hilbert scheme of EF3, motivated by a celebrated example for the Hilbert scheme of space curves due to Mumford.