English

Categorification of a parabolic Hecke module via sheaves on moment graphs

Representation Theory 2016-01-20 v3 Commutative Algebra

Abstract

We investigate certain categories, associated by Fiebig with the geometric representation of a Coxeter system, via sheaves on Bruhat graphs. We modify Fiebig's definition of translation functors in order to extend it to the singular setting and use it to categorify a parabolic Hecke module. As an application we obtain a combinatorial description of indecomposable projective objects of (truncated) non-critical singular blocks of (a deformed version of) category O\mathcal{O}, using indecomposable special modules over the structure algebra of the corresponding Bruhat graph.

Keywords

Cite

@article{arxiv.1208.1492,
  title  = {Categorification of a parabolic Hecke module via sheaves on moment graphs},
  author = {Martina Lanini},
  journal= {arXiv preprint arXiv:1208.1492},
  year   = {2016}
}

Comments

26 pages, substantially revised version. To appear in Pac. J. Math