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相关论文: A maj-inv bijection for C_2 \wr A_n

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In this paper, we give a bijection between rooted labeled ordered forests with a selected subset of their leaves and the regions of the type $C$ Catalan arrangement in $\R^n$. We thus obtain a bijective proof of the well-known enumeration…

组合数学 · 数学 2020-04-22 Anne Micheli , Vu Nguyen Dinh

We present a short proof of MacMahon's classic result that the number of permutations with $k$ inversions equals the number whose major index (sum of positions at which descents occur) is $k$

组合数学 · 数学 2022-07-13 Michael J. Collins

We prove that the Mahonian-Stirling pairs of permutation statistics $(\sor, \cyc)$ and $(\inv, \mathrm{rlmin})$ are equidistributed on the set of permutations that correspond to arrangements of $n$ non-atacking rooks on a Ferrers board with…

组合数学 · 数学 2012-06-07 Svetlana Poznanovik

We give a direct combinatorial proof of the $q,t$-symmetry relation $\tilde H_{\mu}(X;q,t)=\tilde H_{\mu'}(X;t,q)$ in the Macdonald polynomials $\tilde H_\mu$ at the specialization $q=1$. The bijection demonstrates that the Macdonald inv…

组合数学 · 数学 2016-11-22 Maria Gillespie , Ryan Kaliszewski , Jennifer Morse

We prove a conjecture of Haglund which can be seen as an extension of the equidistribution of the inversion number and the major index over permutations to ordered set partitions. Haglund's conjecture implicitly defines two statistics on…

组合数学 · 数学 2014-09-04 Jeffrey B. Remmel , Andrew Timothy Wilson

Arc permutations, which were originally introduced in the study of triangulations and characters, have recently been shown to have interesting combinatorial properties. The first part of this paper continues their study by providing signed…

组合数学 · 数学 2014-09-18 Sergi Elizalde , Yuval Roichman

In this paper, we give a new bijective proof of a multiset analogue of even-odd permutations identity. This multiset version is equivalent to the original coin arrangements lemma which is a key combinatorial lemma in the Sherman's Proof of…

组合数学 · 数学 2022-06-06 Hossein Teimoori Faal

Arnol'd proved in 1992 that Springer numbers enumerate the Snakes, which are type $B$ analogs of alternating permutations. Chen, Fan and Jia in 2011 introduced the labeled ballot paths and established a ``hard'' bijection with snakes.…

组合数学 · 数学 2025-01-03 Shaoshi Chen , Yang Li , Zhicong Lin , Sherry H. F. Yan

Foata and Zeilberger defined the graphical major index, $\mathrm{maj}'_U$, and the graphical inversion index, $\mathrm{inv}'_U$, for words. These statistics are a generalization of the classical permutation statistics $\mathrm{maj}$ and…

组合数学 · 数学 2016-07-04 Amy Grady , Svetlana Poznanović

We provide two explicit bijections demonstrating that, among permutations, the number of invisible inversions is equidistributed with the number of occurrences of the vincular pattern 13-2 after sorting the set of runs.

组合数学 · 数学 2021-11-05 Michael Coopman , Martin Rubey

We introduce a statistic $\pmaj$ on partitions of $[n]=\{1,2,..., n\}$, and show that it is equidistributed with the number of 2-crossings over partitions of $[n]$ with given sets of minimal block elements and maximal block elements. This…

组合数学 · 数学 2007-05-23 William Y. C Chen , Ira M. Gessel , Catherine H. Yan , Arthur L. B. Yang

We present a bijection between cyclic permutations of {1,2,...,n+1} and permutations of {1,2,...,n} that preserves the descent set of the first n entries and the set of weak excedances. This non-trivial bijection involves a Foata-like…

组合数学 · 数学 2012-02-02 Sergi Elizalde

In this paper we look at polynomials arising from statistics on the classes of involutions, $I_n$, and involutions with no fixed points, $J_n$, in the symmetric group. Our results are motivated by F. Brenti's conjecture which states that…

组合数学 · 数学 2007-05-23 W. M. B. Dukes

Bj\"orner and Wachs defined a major index for labeled plane forests and showed that it has the same distribution as the number of inversions. We define and study the distributions of a few other natural statistics on labeled forests.…

组合数学 · 数学 2015-08-24 Amy Grady , Svetlana Poznanovik

For each positive integer $n$, we construct a bijection between the odd partitions and the distinct partitions of $n$ which extends Bressoud's bijection between the odd-and-distinct partitions of $n$ and the splitting partitions of $n$. We…

组合数学 · 数学 2018-03-30 John Murray

We present a simplified variant of Biane's bijection between permutations and 3-colored Motzkin paths with weight that keeps track of the inversion number, excedance number and a statistic so-called depth of a permutation. This generalizes…

组合数学 · 数学 2024-06-25 Sen-Peng Eu , Tung-Shan Fu , Yuan-Hsun Lo

We present a bijection between 321- and 132-avoiding permutations that preserves the number of fixed points and the number of excedances. This gives a simple combinatorial proof of recent results of Robertson, Saracino and Zeilberger, and…

组合数学 · 数学 2007-05-23 Sergi Elizalde , Igor Pak

Recently Cheng et al. (Adv. in Appl. Math. 143 (2023) 102451) generalized the inversion number to partial permutations, which are also known as Laguerre digraphs, and asked for a suitable analogue of MacMahon's major index. We provide such…

组合数学 · 数学 2024-04-03 Ming-Jian Ding , Jiang Zeng

A conjecture by Deutsch, Kitaev, and Remmel states that the triples of permutation statistics $(S_{10}, S_{12}, S_{17})$ and $(S_{12}, S_{10} ,S_{17})$ are equidistributed over the symmetric group $\mathfrak{S}_n$. Here, $S_{10}$ enumerates…

组合数学 · 数学 2026-03-17 Umesh Shankar

On the set of permutations of a finite set, we construct a bijection which maps the 3-vector of statistics $(maj-exc,des,exc)$ to a 3-vector $(maj\_2,\widetilde{des\_2},inv\_2)$ associated with the $q$-Eulerian polynomials introduced by…

组合数学 · 数学 2015-06-25 Ange Bigeni