Lorenzo La Porta: Singularities in the Ekedahl--Oort stratification

Number theory seminar: Lorenzo La Porta (Università of Padova)

Singularities in the Ekedahl--Oort stratification

I will discuss recent results on the singularities of unions
of Ekedahl--Oort strata in the special fibres of some Shimura varieties.
These results were obtained by studying the geometry of some natural
period spaces in positive characteristic, the stacks of G-zips, and
their relative flag spaces. I will present the main theorems, mention
some applications and provide an overview of the techniques involved.
This is joint work with Jean-Stefan Koskivirta and Stefan Reppen.