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3 votes
2 answers
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Asymptotics of A000613

The general linear group $GL_n(\mathbb{F}_2)$ acts on the powerset $2^{{\mathbb{F}_2}^n \setminus \{0\}}$ by multiplication: $A \cdot S := \{Ax \in {\mathbb{F}_2}^n : \, x \in S\}$, for an invertible ...
Colin Tan's user avatar
  • 331
0 votes
1 answer
116 views

Enumerating (i.e. generating one by one) matrices of given rank over a finite field

Let be given positive integers $m,n,r$, with $r \leq \min(m, n)$, and a finite field of $q$ elements $\mathbb{F}_q$. I'm looking for an efficient algorithm to enumerate (i.e., generate one by one) all ...
Kleo's user avatar
  • 43
0 votes
0 answers
298 views

Question on rank of matrices over $\mathbb F_2$

$A$ is a square matrix in $\mathbb F_2^{n\times n}$ of rank $k\leq n-1$. $B$ is a square matrix in $\mathbb F_2^{n\times n}$ of rank $n$. $T$ is a square matrix in $\mathbb F_2^{n\times n}$ of rank $1$...
Turbo's user avatar
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2 votes
0 answers
71 views

Bijections between binary sequences and primitive elements in a finite field [duplicate]

Let $n>1$ be a natural number. We call a binary sequence $(b_1,\ldots, b_n)\in \{0,1\}^n$ $rigid$ if it is not a proper power of a sequence of shorter length. So for example $(0,1,0,1) = (0,1)^2$ ...
Ehud Meir's user avatar
  • 5,039
5 votes
1 answer
764 views

Conjugacy classes in $GL_{n}(Z / pZ)$

Let $p$ be a prime number and $G=GL_n ( \mathbb{Z} / p \mathbb{Z} )$. Consider the set $U$ of upper-triangular matrices of $G$ having entries of $1$ on the diagonal. The cardinality of $U$ is $p^{\...
Nourddine Snanou's user avatar
6 votes
1 answer
303 views

Maximum number of elements in union of subspaces

Let $V$ be a $m$-dimensional vector space over $\mathbb{F}_q$ and $1<\ell<m-1$. Let $r$ be a positive integer such that $r\ell\leq m$. QUESTION. What is the maximum number of elements in the ...
user100393's user avatar
3 votes
0 answers
230 views

On weight enumerators of codes

Are there $[n,k]_q$ constant rate $\frac kn$ and constant alphabet linear code families with automorphism group of size $\Omega((n-n^\beta)!)$ that have minimum distance $d=O(n^\alpha)$ and number of ...
Turbo's user avatar
  • 13.9k
6 votes
0 answers
342 views

What is known about the $q$-analogue of the simplex?

I am interested in the field with one element. I am thus interested in combinatorial interpretations of the Gaussian binomial coefficients. Richard Stanley's "Enumerative combinatorics" mentions ...
Andrius Kulikauskas's user avatar
3 votes
1 answer
237 views

Number of linearly bisected subsets in finite vector space $F_2^n$

We consider the $n$-dimenstional finite vector space $\mathbb{F}_2^{n}$ over the finite field of two elements. For a subset $A\subseteq \mathbb{F}_2^{n}$ of even size $|A|=2m$ and a linear form $l\in(\...
user50982's user avatar
  • 133
3 votes
2 answers
256 views

Picking codewords that are close

I posted this question in https://math.stackexchange.com/questions/1142698/picking-codewords-that-are-close a week back. Let $[n,k,d]$ be a linear code over $\Bbb F_q$ with minimum distance $d$ and ...
Turbo's user avatar
  • 13.9k
6 votes
1 answer
372 views

A parity counting problem for subsets over finite fields

Let ${\mathbb F}_p$ be the prime field of $p$ elements and $b$ be an element in ${\mathbb F}_p$. For a subset $T\subseteq {\mathbb F}_p$, define $$Bias(T)=|N_e( {\mathbb F}_p,b)-N_o( {\mathbb F}_p,b)|...
Joe Franklin's user avatar