English

Generic Newton points and the Newton poset in Iwahori double cosets

Algebraic Geometry 2021-03-02 v3 Combinatorics

Abstract

We consider the Newton stratification on Iwahori double cosets in the loop group of a reductive group. We describe a group-theoretic condition on the generic Newton point, called cordiality, under which the Newton poset (i.e. the index set for non-empty Newton strata) is saturated and Grothendieck's conjecture on closures of the Newton strata holds. Finally, we give several large classes of Iwahori double cosets for which this condition is satisfied by studying certain paths in the associated quantum Bruhat graph.

Keywords

Cite

@article{arxiv.1902.02415,
  title  = {Generic Newton points and the Newton poset in Iwahori double cosets},
  author = {Elizabeth Milićević and Eva Viehmann},
  journal= {arXiv preprint arXiv:1902.02415},
  year   = {2021}
}

Comments

17 pages, 1 figure; expanded introduction, generalized main theorem, changed section numbers; final version to appear in Forum of Mathematics, Sigma v3: no mathematical changes, additional funding accredited