中文

Ad-幂零理想与Shi超平面排列

组合数学 2013-09-11 v3 表示论

摘要

我们将Shi双射从Borel子代数情形推广到抛物子代数。在此过程中,自然地出现了II-删除的Shi排列Shi(I)\texttt{Shi}(I)。该排列介于Coxeter排列Cox\texttt{Cox}和Shi排列Shi\texttt{Shi}之间,并以某种对称的方式打破了Shi\texttt{Shi}的对称性。我们特别地显式确定了An1A_{n-1}CnC_nShi(I)\texttt{Shi}(I)的特征多项式χ(Shi(I),t)\chi(\texttt{Shi}(I), t)。更一般地,设Shi(G)\texttt{Shi}(G)是介于Cox\texttt{Cox}Shi\texttt{Shi}之间的任意排列。Armstrong和Rhoades最近给出了An1A_{n-1}χ(Shi(G),t)\chi(\texttt{Shi}(G), t)公式。受其结果的启发,我们得到了BnB_nCnC_nDnD_nχ(Shi(G),t)\chi(\texttt{Shi}(G), t)公式。

关键词

引用

@article{arxiv.1205.6632,
  title  = {Ad-nilpotent ideals and The Shi arrangement},
  author = {Chao-Ping Dong},
  journal= {arXiv preprint arXiv:1205.6632},
  year   = {2013}
}

备注

The third version, quasi-antichains are shown to be in bijection with elements of L(Cox). arXiv admin note: text overlap with arXiv:1009.1655 by other authors