Abstract
Mehta and van der Kallen put a Frobenius splitting on the type A cotangent bundle T∗GLn/B, thereby defining a stratification by compatibly split subvarieties, and they determined a few of the elements of this stratification. We embed T∗GLn/B as a stratum in a larger stratified (and Frobenius split) space GLn/B × Matn whose stratification we determine, thereby giving a full description of the one of Mehta–van der Kallen. The main technique is to endow GLn/B × Matn with a Bruhat atlas, covering it with open sets that are stratified-isomorphic to Bruhat cells (in GL2n/B2n). Among the consequences are that each stratum closure is normal and Cohen–Macaulay.
Sign-in/Register to access full text options 
Free) 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
