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1 vote
0 answers
32 views

Linear involution for Specht modules

Let $n$ be a positive integer and $\lambda$ be a partition of $n$, which we identify with its Young diagram. Let $S^{\lambda}$ be the Specht module associated to $\lambda$. Here the Specht modules are ...
Albert's user avatar
  • 3,052
1 vote
0 answers
92 views

Sum involving ${\frak{S}}_n$-character values and Kostka numbers

Let $\lambda$, $\mu$, and $\rho$ be partitions of $n$ and let $\chi^\lambda_\rho$ and $K_{\lambda \mu}$ denote the associated ${\frak{S}}_n$-character value and Kostka number respectively. Question: ...
Jeanne Scott's user avatar
2 votes
0 answers
106 views

A question about Fomin's local rules for growth diagrams

Let $w\in S_n$. Define the growth diagram of $w$ as follows: Start by an array of $n\times n$ squares, with an $X$ in the i'th column and row $w(i)$ from bottom. Then we obtain $(n+1)^2$ vertices (the ...
Albert's user avatar
  • 3,052
0 votes
0 answers
123 views

How to evaluate $s_\lambda(q,q^2,\cdots,q^m)$? (principal specialisation of the schur function)

It is required to show that $$ s_\lambda(q,q^2,\cdots,q^m) = q^{m(\lambda)}\prod_{i,j \in \lambda}\frac{1-q^{c_{i,j}+m}}{1-q^{h_{i,j}}} $$ where $c_{i,j}=j-i$ is the content of cell $(i,j)$, and $h_{i,...
user avatar
3 votes
0 answers
317 views

Jacobi–Trudi Determinants — how to use the Lindström–Gessel–Viennot Lemma to prove the second identity?

I am reading Bruce Sagan's Combinatorics: The Art of Counting. In $\S$7.2 The Schur Basis of $\mathrm{Sym}$, the author states the formulas involving the Jacobi–Trudi determinants and the Schur ...
user avatar
2 votes
1 answer
94 views

LR-rule and Standard Young Tableau counting

given that $s_\lambda s_\mu=\sum_{\nu} C_{\lambda \mu}^\nu s_\nu$ with $\vert \lambda\vert +\vert\mu \vert=\vert \nu\vert$, why does apparently also hold that $$h(\lambda) h(\mu) {\vert \nu\vert \...
Wouter M.'s user avatar
  • 910
1 vote
0 answers
136 views

Hook-content polynomial

Let $\lambda$ denote the hook of size $d$ for a fixed integer $d>0$. For $d=2$ there are two kinds of hooks for $d=3$ there are 3 different kind and so on. $c(\Box)$ denote the content of the $\...
GGT's user avatar
  • 1,065
1 vote
0 answers
315 views

Polynomials invariant under specific permutations or subgroups of $S_n$.

The Schur polynomials or the power symmetric polynomials are such that they are invariant under the whole $S_n$. Are there polynomials which are invariant only under a chosen permutation group element ...
gradstudent's user avatar
2 votes
1 answer
119 views

(representation theoretic) meaning of sum over even rows of a Young tableau

Think of a Young tableau $R$ as composed by $d$ rows with number of elements $\mu_i:=\mu_i^R$ $\mu_1 \geq \mu_2 \geq \cdots \geq \mu_d > \mu_{d+1}=0$ (and $\mu_i =0\, \forall i >d$) and define $\...
jj_p's user avatar
  • 2,390
1 vote
2 answers
1k views

Combinatorial definition of Hall–Littlewood polynomials (sum over SSYT?)

Hall–Littlewood polynomials $P_\lambda(x;t)$ is an important deformation of Schur polynomials forming a basis in the ring of symmetric polynomials over $\mathbb Z[t]$. There are various definitions, ...
Grigory M's user avatar
  • 17.6k
3 votes
0 answers
247 views

Cauchy Identity for a specialized product of Schur polynomials

Let $\lambda=(\lambda_1,\lambda_2,\cdots,\lambda_d)$ be a partition, with $|\lambda|=n$. Let $\nu=\nu(\lambda):=(\lambda_1-1,\lambda_2,\cdots,\lambda_d).$ In other words, $\nu$ is obtained from $\...
Alex R.'s user avatar
  • 32.9k
1 vote
0 answers
188 views

Dimension of the Image of Young Projectors corresponding to Tensor factors.

Suppose I define the action of the symmetric group on abstract tensors as shuffling indices. I know this is very naive. I apologise, I am a physicist and working on a problem that involves tensors ...
user40469's user avatar