English

Torus fixed points in Schubert varieties and normalized median Genocchi numbers

Representation Theory 2016-06-15 v2 Algebraic Geometry Combinatorics

Abstract

We give a new proof for the fact that the number of torus fixed points for the degenerated flag variety is equal to the normalized median Genocchi number, using the identification with a certain Schubert variety. We further study the torus fixed points for the symplectic degenerated flag variety and develop a combinatorial model, symplectic Dellac configurations, so parametrize them. The number of these symplectic fixed points is conjectured to be the median Euler number.

Keywords

Cite

@article{arxiv.1504.03980,
  title  = {Torus fixed points in Schubert varieties and normalized median Genocchi numbers},
  author = {Xin Fang and Ghislain Fourier},
  journal= {arXiv preprint arXiv:1504.03980},
  year   = {2016}
}

Comments

title changed, 12 pages, to appear in S\'eminaire Lotharingien de Combinatoire

R2 v1 2026-06-22T09:16:40.595Z