No Arabic abstract
For non-negative integers $n$ and $k$ with $n ge k$, a {em $k$-minor} of a partition $lambda = [lambda_1, lambda_2, dots]$ of $n$ is a partition $mu = [mu_1, mu_2, dots]$ of $n-k$ such that $mu_i le lambda_i$ for all $i$. The multiset $widehat{M}_k(lambda)$ of $k$-minors of $lambda$ is defined as the multiset of $k$-minors $mu$ with multiplicity of $mu$ equal to the number of standard Young tableaux of skew shape $lambda / mu$. We show that there exists a function $G(n)$ such that the partitions of $n$ can be reconstructed from their multisets of $k$-minors if and only if $k le G(n)$. Furthermore, we prove that $lim_{n rightarrow infty} G(n)/n = 1$ with $n-G(n) = O(n/log n)$. As a direct consequence of this result, the irreducible representations of the symmetric group $S_n$ can be reconstructed from their restrictions to $S_{n-k}$ if and only if $k le G(n)$ for the same function $G(n)$. For a minor $mu$ of the partition $lambda$, we study the excitation factor $E_mu (lambda)$, which appears as a crucial part in Naruses Skew-Shape Hook Length Formula. We observe that certain excitation factors of $lambda$ can be expressed as a $mathbb{Q}[k]$-linear combination of the elementary symmetric polynomials of the hook lengths in the first row of $lambda$ where $k = lambda_1$ is the number of cells in the first row of $lambda$.
A set partition is said to be $(k,d)$-noncrossing if it avoids the pattern $12... k12... d$. We find an explicit formula for the ordinary generating function of the number of $(k,d)$-noncrossing partitions of ${1,2,...,n}$ when $d=1,2$.
The notion of broken $k$-diamond partitions was introduced by Andrews and Paule. Let $Delta_{k}(n)$ denote the number of broken $k$-diamond partitions of $n$ for a fixed positive integer $k$. In this paper, we establish new infinite families of broken $k$-diamond partition congruences.
Let $p_{-k}(n)$ enumerate the number of $k$-colored partitions of $n$. In this paper, we establish some infinite families of congruences modulo 25 for $k$-colored partitions. Furthermore, we prove some infinite families of Ramanujan-type congruences modulo powers of 5 for $p_{-k}(n)$ with $k=2, 6$, and $7$. For example, for all integers $ngeq0$ and $alphageq1$, we prove that begin{align*} p_{-2}left(5^{2alpha-1}n+dfrac{7times5^{2alpha-1}+1}{12}right) &equiv0pmod{5^{alpha}} end{align*} and begin{align*} p_{-2}left(5^{2alpha}n+dfrac{11times5^{2alpha}+1}{12}right) &equiv0pmod{5^{alpha+1}}. end{align*}
A generalized crank ($k$-crank) for $k$-colored partitions is introduced. Following the work of Andrews-Lewis and Ji-Zhao, we derive two results for this newly defined $k$-crank. Namely, we first obtain some inequalities between the $k$-crank counts $M_{k}(r,m,n)$ for $m=2,3$ and $4$, then we prove the positivity of symmetrized even $k$-crank moments weighted by the parity for $k=2$ and $3$. We conclude with several remarks on furthering the study initiated here.
Johnson recently proved Armstrongs conjecture which states that the average size of an $(a,b)$-core partition is $(a+b+1)(a-1)(b-1)/24$. He used various coordinate changes and one-to-one correspondences that are useful for counting problems about simultaneous core partitions. We give an expression for the number of $(b_1,b_2,cdots, b_n)$-core partitions where ${b_1,b_2,cdots,b_n}$ contains at least one pair of relatively prime numbers. We also evaluate the largest size of a self-conjugate $(s,s+1,s+2)$-core partition.