English

On decomposition of Bott-Samelson sheaves

Representation Theory 2012-01-11 v2

Abstract

We give an exact algorithm to calculate (under some GKM-restriction) the matrix describing the embedding \B(\s)x\B(\s)x\B(\s)_x\subset\B(\s)^x, where the first module is the costalk and the second one is the stalk at xx of a Bott-Samelson module (sheaf) \B(\s)\B(\s). This allows us to calculate the first few terms of the decomposition of \B(\s)\B(\s) into a sum of indecomposable modules (sheaves) and to calculate the characters of Braden--MacPherson sheaves in some previously unknown cases.

Keywords

Cite

@article{arxiv.1201.1396,
  title  = {On decomposition of Bott-Samelson sheaves},
  author = {Vladimir Shchigolev},
  journal= {arXiv preprint arXiv:1201.1396},
  year   = {2012}
}
R2 v1 2026-06-21T20:01:14.712Z