scholarly journals Families of Major Index Distributions: Closed Forms and Unimodality

10.37236/8585 ◽  
2019 ◽  
Vol 26 (3) ◽  
Author(s):  
William J. Keith
Keyword(s):  
Schur Functions ◽  
Positive Answer ◽  
Schur Function ◽  
Young Tableaux ◽  
Large Collection ◽  
Major Index ◽  
The Family ◽  
Standard Young Tableaux ◽  
Principal Specialization

Closed forms for $f_{\lambda,i} (q) := \sum_{\tau \in SYT(\lambda) : des(\tau) = i} q^{maj(\tau)}$, the distribution of the major index over standard Young tableaux of given shapes and specified number of descents, are established for a large collection of $\lambda$ and $i$. Of particular interest is the family that gives a positive answer to a question of Sagan and collaborators. All formulas established in the paper are unimodal, most by a result of Kirillov and Reshetikhin. Many can be identified as specializations of Schur functions via the Jacobi-Trudi identities. If the number of arguments is sufficiently large, it is shown that any finite principal specialization of any Schur function $s_\lambda(1,q,q^2,\dots,q^{n-1})$ has a combinatorial realization as the distribution of the major index over a given set of tableaux.

scholarly journals Number of standard strong marked tableaux

2013 ◽  
Vol DMTCS Proceedings vol. AS,... (Proceedings) ◽  
Author(s):  
Susanna Fishel ◽  
Matjaž Konvalinka
Keyword(s):  
Schur Functions ◽  
Young Tableaux ◽  
Nous Proposons ◽  
Hook Length ◽  
International Audience ◽  
Standard Young Tableaux

International audience Many results involving Schur functions have analogues involving $k-$Schur functions. Standard strong marked tableaux play a role for $k-$Schur functions similar to the role standard Young tableaux play for Schur functions. We discuss results and conjectures toward an analogue of the hook length formula. De nombreux résultats impliquant les fonctions de Schur possèdent des analogues pour les fonctions de k-Schur. Les tableaux standard fortement marqués jouent un rôle pour les fonctions de k-Schur semblable á celui joué par les tableaux de Young pour les fonctions de Schur. Nous proposons ici des résultats et conjectures vers un analogue de la formule des équerres.

scholarly journals Hook-content Formulae for Symplectic and Orthogonal Tableaux

2012 ◽  
Vol 55 (3) ◽  
pp. 462-473
Author(s):  
Peter S. Campbell ◽  
Anna Stokke
Keyword(s):  
Young Diagram ◽  
Schur Functions ◽  
Schur Function ◽  
Young Tableaux

AbstractBy considering the specialisation sλ(1, q, q2, … , qn–1) of the Schur function, Stanley was able to describe a formula for the number of semistandard Young tableaux of shape λ in terms of the contents and hook lengths of the boxes in the Young diagram. Using specialisations of symplectic and orthogonal Schur functions, we derive corresponding formulae, first given by El Samra and King, for the number of semistandard symplectic and orthogonal λ-tableaux.

scholarly journals A Cornucopia of Quasi-Yamanouchi Tableaux

10.37236/8082 ◽  
2019 ◽  
Vol 26 (1) ◽  
Author(s):  
George Wang
Keyword(s):  
Schur Functions ◽  
Product Formula ◽  
Lattice Paths ◽  
Young Tableaux ◽  
Jack Polynomials ◽  
Symmetric Polynomials ◽  
Descent Set ◽  
Standard Young Tableaux ◽  
Weighted Lattice Paths ◽  
Coinvariant Algebra

Quasi-Yamanouchi tableaux are a subset of semistandard Young tableaux and refine standard Young tableaux. They are closely tied to the descent set of standard Young tableaux and were introduced by Assaf and Searles to tighten Gessel's fundamental quasisymmetric expansion of Schur functions. The descent set and descent statistic of standard Young tableaux repeatedly prove themselves useful to consider, and as a result, quasi-Yamanouchi tableaux make appearances in many ways outside of their original purpose. Some examples, which we present in this paper, include the Schur expansion of Jack polynomials, the decomposition of Foulkes characters, and the bigraded Frobenius image of the coinvariant algebra. While it would be nice to have a product formula enumeration of quasi-Yamanouchi tableaux in the way that semistandard and standard Young tableaux do, it has previously been shown by the author that there is little hope on that front. The goal of this paper is to address a handful of the numerous alternative enumerative approaches. In particular, we present enumerations of quasi-Yamanouchi tableaux using $q$-hit numbers, semistandard Young tableaux, weighted lattice paths, and symmetric polynomials, as well as the fundamental quasisymmetric and monomial quasisymmetric expansions of their Schur generating function.

scholarly journals A Relationship between the Major Index for Tableaux and the Charge Statistic for Permutations

10.37236/1942 ◽  
2005 ◽  
Vol 12 (1) ◽  
Author(s):  
Kendra Killpatrick
Keyword(s):  
Linear Group ◽  
Generating Function ◽  
General Linear Group ◽  
General Linear ◽  
Combinatorial Proof ◽  
Young Tableaux ◽  
Major Index ◽  
Combinatorial Interpretations ◽  
Standard Young Tableaux ◽  
Kostka Number

The widely studied $q$-polynomial $f^{\lambda}(q)$, which specializes when $q=1$ to $f^{\lambda}$, the number of standard Young tableaux of shape $\lambda$, has multiple combinatorial interpretations. It represents the dimension of the unipotent representation $S_q^{\lambda}$ of the finite general linear group $GL_n(q)$, it occurs as a special case of the Kostka-Foulkes polynomials, and it gives the generating function for the major index statistic on standard Young tableaux. Similarly, the $q$-polynomial $g^{\lambda}(q)$ has combinatorial interpretations as the $q$-multinomial coefficient, as the dimension of the permutation representation $M_q^{\lambda}$ of the general linear group $GL_n(q)$, and as the generating function for both the inversion statistic and the charge statistic on permutations in $W_{\lambda}$. It is a well known result that for $\lambda$ a partition of $n$, $dim(M_q^{\lambda}) = \Sigma_{\mu} K_{\mu \lambda} dim(S_q^{\mu})$, where the sum is over all partitions $\mu$ of $n$ and where the Kostka number $K_{\mu \lambda}$ gives the number of semistandard Young tableaux of shape $\mu$ and content $\lambda$. Thus $g^{\lambda}(q) - f^{\lambda}(q)$ is a $q$-polynomial with nonnegative coefficients. This paper gives a combinatorial proof of this result by defining an injection $f$ from the set of standard Young tableaux of shape $\lambda$, $SYT(\lambda)$, to $W_{\lambda}$ such that $maj(T) = ch(f(T))$ for $T \in SYT(\lambda)$.

scholarly journals Row bounds needed to justifiably express flagged Schur functions with Gessel-Viennot determinants

2021 ◽  
Vol vol. 23 no. 1 (Combinatorics) ◽  
Author(s):  
Robert A. Proctor ◽  
Matthew J. Willis
Keyword(s):  
Schur Functions ◽  
Equivalence Classes ◽  
Catalan Numbers ◽  
Lattice Paths ◽  
Schur Function ◽  
Young Tableaux ◽  
Meta Data ◽  
Key Polynomials ◽  
Demazure Characters ◽  
Necessary And Sufficient

Let $\lambda$ be a partition with no more than $n$ parts. Let $\beta$ be a weakly increasing $n$-tuple with entries from $\{ 1, ... , n \}$. The flagged Schur function in the variables $x_1, ... , x_n$ that is indexed by $\lambda$ and $\beta$ has been defined to be the sum of the content weight monomials for the semistandard Young tableaux of shape $\lambda$ whose values are row-wise bounded by the entries of $\beta$. Gessel and Viennot gave a determinant expression for the flagged Schur function indexed by $\lambda$ and $\beta$; this could be done since the pair $(\lambda, \beta)$ satisfied their "nonpermutable" condition for the sequence of terminals of an $n$-tuple of lattice paths that they used to model the tableaux. We generalize flagged Schur functions by dropping the requirement that $\beta$ be weakly increasing. Then for each $\lambda$ we give a condition on the entries of $\beta$ for the pair $(\lambda, \beta)$ to be nonpermutable that is both necessary and sufficient. When the parts of $\lambda$ are not distinct there will be multiple row bound $n$-tuples $\beta$ that will produce the same set of tableaux. We accordingly group the bounding $\beta$ into equivalence classes and identify the most efficient $\beta$ in each class for the determinant computation. We recently showed that many other sets of objects that are indexed by $n$ and $\lambda$ are enumerated by the number of these efficient $n$-tuples. We called these counts "parabolic Catalan numbers". It is noted that the $GL(n)$ Demazure characters (key polynomials) indexed by 312-avoiding permutations can also be expressed with these determinants. Comment: 22 pages, 5 figures, 4 tables. Identical to v.5, except for the insertion of a reference and the DMTCS journal's publication meta data

scholarly journals Hook formulas for skew shapes

2020 ◽  
Vol DMTCS Proceedings, 28th... ◽  
Author(s):  
Alejandro H. Morales ◽  
Igor Pak ◽  
Greta Panova
Keyword(s):  
General Formula ◽  
Schur Functions ◽  
Product Formula ◽  
Young Tableaux ◽  
Hook Length ◽  
International Audience ◽  
Border Strip ◽  
Standard Young Tableaux ◽  
Skew Schur Functions ◽  
Reverse Plane

International audience The celebrated hook-length formula gives a product formula for the number of standard Young tableaux of a straight shape. In 2014, Naruse announced a more general formula for the number of standard Young tableaux of skew shapes as a positive sum over excited diagrams of products of hook-lengths. We give two q-analogues of Naruse's formula for the skew Schur functions and for counting reverse plane partitions of skew shapes. We also apply our results to border strip shapes and their generalizations.

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.

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