Year of Graduation
Geometry of Singular Double Covers
In this work we study stably rationally connected threefolds which are not rational. The first example of such variety was introduced by M.\,Artin and D.\,Mumford, it was a nodal quartic double solid branched over a quartic with 10 nodes. Then S.\,Endrass was showed that Artin——Mumford family of quartic is unique with non-trivial Artin-Mumford obstruction in the class of nodal quartics. We are going to consider sextic double solids. We specify the minimal type of sextic surfaces, such that the double solid has a non-trivial obstruction and then study double solids of minimal type.