A reducible characteristic variety in type A
Representation Theory
2016-11-18 v1 Algebraic Geometry
Abstract
We show that simple highest weight modules for sl_12 may have reducible characteristic variety. This answers a question of Borho-Brylinski and Joseph from 1984. The relevant singularity under Beilinson-Bernstein localization is the (in)famous Kashiwara-Saito singularity. We sketch the rather indirect route via the p-canonical basis, W-graphs and decomposition numbers for perverse sheaves that led us to examine this singularity.
Cite
@article{arxiv.1405.3479,
title = {A reducible characteristic variety in type A},
author = {Geordie Williamson},
journal= {arXiv preprint arXiv:1405.3479},
year = {2016}
}
Comments
13 pages, comments welcome