English

ad-nilpotent $\frak b$-ideals in sl(n) having a fixed class of nilpotence: combinatorics and enumeration

Rings and Algebras 2007-05-23 v1 Combinatorics

Abstract

We study the combinatorics of ad-nilpotent ideals of a Borel subalgebra of sl(n+1,C)sl(n+1,\Bbb C). We provide an inductive method for calculating the class of nilpotence of these ideals and formulas for the number of ideals having a given class of nilpotence. We study the relationships between these results and the combinatorics of Dyck paths, based upon a remarkable bijection between ad-nilpotent ideals and Dyck paths. Finally, we propose a (q,t)-analogue of the Catalan number CnC_n. These (q,t)-Catalan numbers count on the one hand ad-nilpotent ideals with respect to dimension and class of nilpotence, and on the other hand admit interpretations in terms of natural statistics on Dyck paths.

Keywords

Cite

@article{arxiv.math/0004107,
  title  = {ad-nilpotent $\frak b$-ideals in sl(n) having a fixed class of nilpotence: combinatorics and enumeration},
  author = {George E. Andrews and Christian Krattenthaler and Luigi Orsina and Paolo Papi},
  journal= {arXiv preprint arXiv:math/0004107},
  year   = {2007}
}

Comments

19 pages, AmS-TeX