Degenerations of Hilbert schemes and relative VGIT – Lars Halvard Halle (Università di Bologna)


Department of Mathematics, Aula Magna.


Let G be a reductive group acting on a projective variety X.  In Mumford’s Geometric Invariant Theory (GIT),  the formation of a quotient in this situation depends on the choice of a G-linearized ample line bundle on X. In “Variation of GIT” (VGIT), one studies various aspects of this dependence. 
I will report on joint work with K. Hulek and Z. Zhang, and explain how some central results in VGIT can be extended to a relative setting. Our main motivation was to apply these results to the study of certain Hilbert scheme degenerations constructed as relative GIT quotients. In the second part of the talk, I will indicate how VGIT can be used to provide a conceptual understanding of the (semi)stable locus in this quotient construction.

Further information is available on the event page on the Indico platform.

Back to top