Twists of Drinfeld-Stuhler modular varieties

Hodge-type decomposition for de Rham cohomology of $ p $-adically uniformized varieties

We prove a Hodge-type decomposition for the de-Rham cohomology of $ p$-adically uniformized varieties by the product of Drinfeld's symmetric spaces. It is based on work of Schneider, Stuhler, Iovita and Spiess on the cohomology of Drinfeld's symmetric space.

The de Rham cohomology of Drinfeld's half space

Let X be Drinfeld's half space over a p-adic field K. The de Rham cohomology of X was first computed by Schneider and Stuhler. Afterwards there were given different proofs by Alon, de Shalit, Iovita and Spiess. This paper presents yet another approach for the determination of these invariants by analysing the de Rham complex of X from the viewpoint of recent results by the author.

Torsion of Drinfeld modules and equicharacteristic unimodular Galois covers

We prove that the groups PSL(r,q^d) can be realized F_q(T)-regularly as Galois groups over the purely transcendental field F_q(T)(t_1,...,t_{r-1}) if r is even and r/2 is coprime to q^d-1. The method is to use twisted moduli schemes of Drinfeld modules (a la Shih). If one has sufficient control over modular forms, it can be made into an algorithm to find explicit equations. We do this for PSL(2,q^2) using Drinfeld modular forms.

Beilinson-Drinfeld Schubert簇的parahoric群概形与扭曲整体Demazure模

Beilinson-Drinfeld Schubert varieties of parahoric group schemes and twisted global Demazure modules

本文研究parahoric群概形的Beilinson-Drinfeld Schubert簇，证明其平坦性并确定Picard群，建立整体Demazure模理论，推广了非扭曲情形下的对偶结果。

Curves over global fields violating the Hasse Principle

In response to a question of B. Poonen, we exhibit for each global field k an algebraic curve over k which violates the Hasse Principle. In fact we can find such examples among Atkin-Lehner twists of certain elliptic modular curves and -- in positive characteristic -- Drinfeld modular curves. Our main tool is a refinement of the "Twist Anti-Hasse Principle" (TAHP). We also use TAHP to construct further Hasse Principle violations, for instance among curves over any number field of any given genus g which is at least 2.