English

Degree bounds for type-A weight rings and Gelfand--Tsetlin semigroups

Algebraic Geometry 2008-12-06 v2 Representation Theory

Abstract

A weight ring in type A is the coordinate ring of the GIT quotient of the variety of flags in \Cn\C^n modulo a twisted action of the maximal torus in \SL(n,\C)\SL(n,\C). We show that any weight ring in type A is generated by elements of degree strictly less than the Krull dimension, which is at worst O(n2)O(n^2). On the other hand, we show that the associated semigroup of Gelfand--Tsetlin patterns can have an essential generator of degree exponential in nn.

Keywords

Cite

@article{arxiv.0812.0826,
  title  = {Degree bounds for type-A weight rings and Gelfand--Tsetlin semigroups},
  author = {Benjamin J. Howard and Tyrrell B. McAllister},
  journal= {arXiv preprint arXiv:0812.0826},
  year   = {2008}
}

Comments

12 pages, 1 figure, v2: hyperref package options changed to suit non-pdf latex

R2 v1 2026-06-21T11:48:08.493Z