Resumen de Beilinson–Drinfeld Schubert varieties of parahoric group schemes and twisted global Demazure modules
Let G be a parahoric Bruhat–Tits group scheme arising from a -curve C and a certain -action on a simple algebraic group G for some finite cyclic group . We prove the flatness of Beilinson–Drinfeld Schubert varieties of G, we determine the rigidified Picard group of the Beilinson–Drinfeld Grassmannian GrG,Cn of G, and we establish the factorizable and equivariant structures on rigidified line bundles over GrG,Cn . We develop an algebraic theory of global Demazure modules of twisted current algebras, and using our geometric results we prove that when C = A1, the spaces of global sections of line bundles on BD Schubert varieties of G are dual to the twisted global Demazure modules. This generalizes the work of Dumanski–Feigin–Finkelberg in the untwisted setting.
