English

On the little Weyl group of a real spherical space

Representation Theory 2022-10-28 v2 Group Theory

Abstract

In the present paper we further the study of the compression cone of a real spherical homogeneous space Z=G/HZ=G/H. In particular we provide a geometric construction of the little Weyl group of ZZ introduced recently by Knop and Kr\"otz. Our technique is based on a fine analysis of limits of conjugates of the subalgebra Lie(H)\mathrm{Lie}(H) along one-parameter subgroups in the Grassmannian of subspaces of Lie(G)\mathrm{Lie}(G). The little Weyl group is obtained as a finite reflection group generated by the reflections in the walls of the compression cone.

Keywords

Cite

@article{arxiv.2006.03516,
  title  = {On the little Weyl group of a real spherical space},
  author = {Job J. Kuit and Eitan Sayag},
  journal= {arXiv preprint arXiv:2006.03516},
  year   = {2022}
}

Comments

Final version, published in Mathematische Annalen