arXivDaily arXiv每日学术速递 周一至周五更新
arXiv 2301.00341math.CO
收藏

连接无符号与有符号相对错位排列的自反多项式

Self-reciprocal polynomials connecting unsigned and signed relative derangements

Ricky X. F. Chen, Yu-Chen Ruan

AI总结:

本文引入有符号相对错位排列的多项式以追踪有符号元素数量,证明其满足递推关系与系数单峰性,并给出组合证明及对偶结果,连接了无符号与有符号相对错位排列。

摘要:

在本文中,我们引入了有符号相对错位排列的(关于$t$的)多项式,用于追踪有符号元素的数量。可以清楚地看到,这些多项式在某种意义上是对称的。注意,相对错位排列是指没有任何有符号元素的排列,即多项式在$t=0$处的求值。此外,所有有符号相对错位排列的数量由$t=1$处的求值给出。因此,多项式的系数连接了无符号和有符号相对错位排列,并展示了赋予元素符号如何影响错位排列的形成。我们首先证明了这些多项式满足的一个递推关系,从而导出系数满足的递推关系。接下来提供了后者的组合证明。我们还证明了系数序列是单峰的。此外,还获得了其他结果。例如,给出了Chen和Zhang先前证明的有符号错位排列与有符号相对错位排列之间关系的一种对偶形式。

英文摘要:

In this paper, we introduce polynomials (in $t$) of signed relative derangements that track the number of signed elements. The polynomials are clearly seen to be in a sense symmetric. Note that relative derangements are those without any signed elements, i.e., the evaluations of the polynomials at $t=0$. Also, the numbers of all signed relative derangements are given by the evaluations at $t=1$. Then the coefficients of the polynomials connect unsigned and signed relative derangements and show how putting elements with signs affects the formation of derangements. We first prove a recursion satisfied by these polynomials which results in a recursion satisfied by the coefficients. A combinatorial proof of the latter is provided next. We also show that the sequences of the coefficients are unimodal. Moreover, other results are obtained. For instance, a kind of dual of a relation between signed derangements and signed relative derangements previously proved by Chen and Zhang is presented.

机构、总结、中文摘要均由AI分析而来,可能存在错误,请以论文正文为准。

↑