Speaker: 

Yuxin Lin

Institution: 

Caltech

Time: 

Thursday, February 15, 2024 - 3:00pm to 4:00pm

Location: 

RH 306

Given a family of abelian covers of P^1 branched at at least four points and a prime p of good reduction, by considering the associated Deligne--Mostow Shimura variety, we obtain lower bounds for the Ekedahl-Oort types, and the Newton polygons, at prime p of the curves in the family. In this paper, we investigate whether such lower bounds are sharp. In particular, we prove sharpeness when the number of branching points is at most five and p sufficiently large. Our result is a generalization under stricter assumptions of Irene Bouw, which proves the analogous statement for the p-rank, and it relies on the notion of Hasse-Witt triple introduced by Ben Moonen.