Graded and Geometric Parabolic Induction for Category
arXiv:1603.00327
Abstract
We prove that the parabolic induction functor on BGG-category associated to a complex reductive Lie algebra is gradable, that is, lifts to graded category as constructed by Beilinson-Ginzburg-Soergel. Graded category is equivalent to a category of stratified mixed Tate motives on a corresponding flag variety as recently defined by Soergel-Wendt. The graded version of parabolic induction is induced by a geometric parabolic induction functor we construct on the level of stratified mixed Tate motives. We also describe the effect of parabolic induction on the level of Soergel modules.
Completely reworked, added the case of singular weights