scholarly journals Rook Placements and Jordan Forms of Upper-Triangular Nilpotent Matrices

10.37236/6888 ◽  
2018 ◽  
Vol 25 (1) ◽  
Author(s):  
Martha Yip
Keyword(s):  
Finite Field ◽  
Weighted Sum ◽  
Young Tableaux ◽  
Canonical Forms ◽  
Combinatorial Formula ◽  
Rook Placements ◽  
Nilpotent Matrices ◽  
Jordan Forms ◽  
Standard Young Tableaux ◽  
Young’S Lattice

The set of $n$ by $n$ upper-triangular nilpotent matrices with entries in a finite field $\mathbb{F}_q$ has Jordan canonical forms indexed by partitions $\lambda \vdash n$. We present a combinatorial formula for computing the number $F_\lambda(q)$ of matrices of Jordan type $\lambda$ as a weighted sum over standard Young tableaux. We construct a bijection between paths in a modified version of Young's lattice and non-attacking rook placements, which leads to a refinement of the formula for $F_\lambda(q)$.

scholarly journals q-Rook placements and Jordan forms of upper-triangular nilpotent matrices

2013 ◽  
Vol DMTCS Proceedings vol. AS,... (Proceedings) ◽  
Author(s):  
Martha Yip
Keyword(s):  
Finite Field ◽  
Weighted Sum ◽  
Canonical Forms ◽  
Combinatorial Formula ◽  
Jordan Type ◽  
Rook Placements ◽  
Nilpotent Matrices ◽  
International Audience ◽  
Jordan Forms

International audience The set of $n$ by $n$ upper-triangular nilpotent matrices with entries in a finite field $F_q$ has Jordan canonical forms indexed by partitions $λ \vdash n$. We study a connection between these matrices and non-attacking q-rook placements, which leads to a combinatorial formula for the number$ F_λ (q)$ of matrices of fixed Jordan type as a weighted sum over rook placements.

scholarly journals Combinatorial Formula for the Hilbert Series of bigraded $S_n$-modules

2009 ◽  
Vol DMTCS Proceedings vol. AK,... (Proceedings) ◽  
Author(s):  
Meesue Yoo
Keyword(s):  
Hilbert Series ◽  
Macdonald Polynomials ◽  
Weighted Sum ◽  
Young Tableaux ◽  
Combinatorial Formula ◽  
Nous Proposons ◽  
International Audience ◽  
Standard Young Tableaux ◽  
Littlewood Polynomial ◽  
The Way

International audience We introduce a combinatorial way of calculating the Hilbert series of bigraded $S_n$-modules as a weighted sum over standard Young tableaux in the hook shape case. This method is based on Macdonald formula for Hall-Littlewood polynomial and extends the result of $A$. Garsia and $C$. Procesi for the Hilbert series when $q=0$. Moreover, we give the way of associating the fillings giving the monomial terms of Macdonald polynomials to the standard Young tableaux. Nous introduisons une méthode combinatoire pour calculer la série de Hilbert de modules bigradués de $S_n$ comme une somme pondérée sur les tableaux de Young standards à la forme crochet. Cette méthode se fonde sur la formule Macdonald pour les polynômes Hall-Littlewood et généralise un résultat de $A$. Garsia et $C$. Procesi pour la série de Hilbert dans le cas $q=0$. De plus, nous proposons une méthode pour associer aux tableaux de Young standards les remplissages des monômes des polynômes de Macdonald.

scholarly journals Homomesy in Products of Two Chains

10.37236/3579 ◽  
2015 ◽  
Vol 22 (3) ◽  
Author(s):  
James Propp ◽  
Tom Roby
Keyword(s):  
Theoretical Framework ◽  
Vector Spaces ◽  
Young Tableaux ◽  
Combinatorial Objects ◽  
Standard Young Tableaux ◽  
Young’S Lattice

Many invertible actions $\tau$ on a set $\mathcal{S}$ of combinatorial objects, along with a natural statistic $f$ on $\mathcal{S}$, exhibit the following property which we dub homomesy: the average of $f$ over each $\tau$-orbit in $\mathcal{S}$ is the same as the average of $f$ over the whole set $\mathcal{S}$. This phenomenon was first noticed by Panyushev in 2007 in the context of the rowmotion action on the set of antichains of a root poset; Armstrong, Stump, and Thomas proved Panyushev's conjecture in 2011. We describe a theoretical framework for results of this kind  that applies more broadly, giving examples in a variety of contexts. These include linear actions on vector spaces, sandpile dynamics, Suter's action on certain subposets of Young's Lattice, Lyness 5-cycles, promotion of rectangular semi-standard Young tableaux, and the rowmotion and promotion actions on certain posets. We give a detailed description of the latter situation for products of two chains.  

scholarly journals A Combinatorial Formula for the Hilbert Series of Bigraded $S_n$-Modules

10.37236/365 ◽  
2010 ◽  
Vol 17 (1) ◽  
Author(s):  
Meesue Yoo
Keyword(s):  
Hilbert Series ◽  
Macdonald Polynomials ◽  
Weighted Sums ◽  
Young Tableaux ◽  
Combinatorial Formula ◽  
Standard Young Tableaux

We prove a combinatorial formula for the Hilbert series of the Garsia-Haiman bigraded $S_n$-modules as weighted sums over standard Young tableaux in the hook shape case. This method is based on the combinatorial formula of Haglund, Haiman and Loehr for the Macdonald polynomials and extends the result of A. Garsia and C. Procesi for the Hilbert series when $q=0$. Moreover, we construct an association of the fillings giving the monomial terms of Macdonald polynomials with the standard Young tableaux.

scholarly journals A Note on Statistical Averages for Oscillating Tableaux

10.37236/4641 ◽  
2015 ◽  
Vol 22 (2) ◽  
Author(s):  
Sam Hopkins ◽  
Ingrid Zhang
Keyword(s):  
Simple Formula ◽  
Perfect Matchings ◽  
Quadratic Polynomial ◽  
Average Weight ◽  
Young Tableaux ◽  
Hidden Symmetry ◽  
Conceptual Proof ◽  
Standard Young Tableaux ◽  
Young’S Lattice

Oscillating tableaux are certain walks in Young's lattice of partitions; they generalize standard Young tableaux. The shape of an oscillating tableau is the last partition it visits and the length of an oscillating tableau is the number of steps it takes. We define a new statistic for oscillating tableaux that we call weight: the weight of an oscillating tableau is the sum of the sizes of all the partitions that it visits.  We show that the average weight of all oscillating tableaux of shape $\lambda$ and length $|\lambda|+2n$ (where $|\lambda|$ denotes the size of $\lambda$ and $n \in \mathbb{N}$) has a surprisingly simple formula: it is a quadratic polynomial in $|\lambda|$ and $n$. Our proof via the theory of differential posets is largely computational. We suggest how the homomesy paradigm of Propp and Roby may lead to a more conceptual proof of this result and reveal a hidden symmetry in the set of perfect matchings.

Standard Young tableaux in a (2,1)-hook and Motzkin paths

2021 ◽  
Vol 344 (7) ◽  
pp. 112395
Author(s):  
Rosena R.X. Du ◽  
Jingni Yu
Keyword(s):  
Young Tableaux ◽  
Standard Young Tableaux ◽  
Motzkin Paths

scholarly journals A direct bijective proof of the hook-length formula

1997 ◽  
Vol Vol. 1 ◽  
Author(s):  
Jean-Christophe Novelli ◽  
Igor Pak ◽  
Alexander V. Stoyanovskii
Keyword(s):  
Young Tableaux ◽  
Hook Length ◽  
Bijective Proof ◽  
International Audience ◽  
Standard Young Tableaux

International audience This paper presents a new proof of the hook-length formula, which computes the number of standard Young tableaux of a given shape. After recalling the basic definitions, we present two inverse algorithms giving the desired bijection. The next part of the paper presents the proof of the bijectivity of our construction. The paper concludes with some examples.

scholarly journals Enumeration of Standard Young Tableaux of Shifted Strips with Constant Width

10.37236/6466 ◽  
2017 ◽  
Vol 24 (2) ◽  
Author(s):  
Ping Sun
Keyword(s):  
Integral Method ◽  
Recurrence Relations ◽  
Young Tableau ◽  
Constant Width ◽  
Young Tableaux ◽  
Pell Number ◽  
Standard Young Tableaux ◽  
Standard Young Tableau

Let $g_{n_1,n_2}$ be the number of standard Young tableau of truncated shifted shape with $n_1$ rows and $n_2$ boxes in each row. By using the integral method this paper derives the recurrence relations of $g_{3,n}$, $g_{n,4}$ and $g_{n,5}$ respectively. Specifically, $g_{n,4}$ is the $(2n-1)$-st Pell number.

scholarly journals Evaluating the Numbers of some Skew Standard Young Tableaux of Truncated Shapes

10.37236/3890 ◽  
2015 ◽  
Vol 22 (1) ◽  
Author(s):  
Ping Sun
Keyword(s):  
Young Tableaux ◽  
Multiple Integrals ◽  
Standard Young Tableaux ◽  
Product Formulas

In this paper the number of standard Young tableaux (SYT) is evaluated by the methods of multiple integrals and combinatorial summations. We obtain the product formulas of the numbers of skew SYT of certain truncated shapes, including the skew SYT $((n+k)^{r+1},n^{m-1}) / (n-1)^r $ truncated by a rectangle or nearly a rectangle, the skew SYT of truncated shape $((n+1)^3,n^{m-2}) / (n-2) \backslash \; (2^2)$, and the SYT of truncated shape $((n+1)^2,n^{m-2}) \backslash \; (2)$.

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