1 citations · 2 across the 11 of their papers we have counts for
17 papers
Decidability of singularities in the Ekedahl--Oort stratification
Jean-Stefan Koskivirta, Lorenzo La Porta
For an abelian type Shimura variety and an odd prime of good reduction, we characterize the regularity in codimension one of Zariski closures of Ekedahl--Oort strata in terms o…
Singularities in the Ekedahl--Oort stratification
Jean-Stefan Koskivirta, Lorenzo La Porta, Stefan Reppen
We give conceptual and combinatorial criteria for the normality and Cohen--Macaulayness of unions of Ekedahl--Oort strata in the special fiber of abelian type Shimura varieties. Fo…
The cone conjecture for vector-valued Siegel automorphic forms
Jean-Stefan Koskivirta
We prove that the effective cone of automorphic vector bundles on the Siegel modular variety of rank in characteristic at a place of good reduction is encoded by the stack…
The stack of -zips is a Mori dream space
Jean-Stefan Koskivirta
We first extend previous results of the author with T. Wedhorn and W. Goldring regarding the existence of -ordinary Hasse invariants for Hodge-type Shimura varieties to other au…
Cohomology vanishing for Ekedahl--Oort strata on Hilbert--Blumenthal Shimura varieties
Jean-Stefan Koskivirta
We prove vanishing results for the th cohomology of automorphic line bundles on the Ekedahl--Oort strata of the special fiber of Hilbert--Blumenthal Shimura varieties. This work…
A vanishing theorem for vector-valued Siegel automorphic forms in characteristic
Jean-Stefan Koskivirta
We show that the space of vector-valued Siegel automorphic forms in characteristic is zero when the weight is outside of an explicit locus. This result is a special case of a g…