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4 votes
1 answer
2k views

Question about LFSR

I am reading a paper and say this "The idea is to load $f(X)$ into LFSR to multiply by $X$ mod $g(X)$(primitive polynomial deg $g=n$). We next compute a polynomial h(X) whose coefficients are given ...
juaninf's user avatar
  • 1,254
2 votes
3 answers
988 views

Polynomials, finite fields and cardinality/dimension considerations

Can someone please give me a hint how to prove that the quotient ring $\mathbb{F}_p[x]/{\langle f\rangle}$, where $f$ is a irreducible polynomial of degree $k$ and $p$ is a prime (and $\langle f\...
user avatar
54 votes
3 answers
18k views

Irreducible polynomial which is reducible modulo every prime

How to show that $x^4+1$ is irreducible in $\mathbb Z[x]$ but it is reducible modulo every prime $p$? For example I know that $x^4+1=(x+1)^4\bmod 2$. Also $\bmod 3$ we have that $0,1,2$ are not ...
palio's user avatar
  • 11.1k
17 votes
2 answers
22k views

Reed Solomon Polynomial Generator

I am developing a sample program to generate a 2D Barcode, using Reed-Solomon error correction codes. By going through this article, I am developing the program. But I couldn't understand how he ...
Dungeon Hunter's user avatar
1 vote
1 answer
316 views

Low degree approximation of the polynomial extension of the logical-or function

Let $x\in\{0,1\}^n$ be a binary vector of dimension $n$, and let $OR(x)$ be the "logical or" function (i.e., returns $1$ if at least one of the coordinates is $1$ and otherwise returns $0$). Consider ...
user avatar
2 votes
1 answer
357 views

Extending the logical-or function to a low degree polynomial over a finite field

Let $x\in\{0,1\}^n$ be a binary vector of dimension $n$, and let $OR(x)$ be the "logical or" function (i.e., returns $1$ if at least one of the coordinates is $1$ and otherwise returns $0$). Is there ...
user avatar
1 vote
1 answer
1k views

Low degree extension

Let $v$ be a binary vector of dimension $n$. Assume that $n$ is a perfect square, then $v$ can be thought of as a function $f:[\sqrt n]\times[\sqrt n]\to \{0,1\}$, where $[\sqrt n]=\{1,\ldots,\sqrt n\}...
user avatar
4 votes
2 answers
4k views

Irreducible polynomial of $\mathrm{GF}(2^{16})$

I'm implementing some code for the Galois field $\mathrm{GF}(2^{16})$. Which irreducible polynomial do you recommend that I use?
Yrlec's user avatar
  • 143
2 votes
1 answer
217 views

Variation over univariate Schwartz–Zippel lemma

Let $n\in\mathbb{N}$ and let $q\in[n,2n]$ be a prime number. In addition, let $s,s':\mathbb{F}_q\to\mathbb{F}_q$ be polynomials of degree $\sqrt{n}$ such that $s\neq s'$. From the Schwartz–...
user avatar
2 votes
1 answer
225 views

Extending a boolean function to a finite field

Let $f:\{1,2,\ldots,n\}\to\{-1,1\}$ be a boolean function. Can I extend $f$ to a polynomial of degree at most $n$ over $\mathbb{F}_q$, where $q\in[n,2n]$ is a prime number. i.e., is there a ...
user avatar
5 votes
3 answers
347 views

Roots of $x^2 + 2x + 2$

I'm trying to show that there are infinitely many values of $p$ such that $x^2 + 2x + 2$ has no roots over $\mathbb{F}_p$. Is this easily solvable? (I kind of came up with it myself so I don't know.)...
badatmath's user avatar
  • 4,075
2 votes
1 answer
108 views

Distinguishing vector distributions induced by polynomials

I am given two sequences of multivariate polynomials $\overline{p}=(p_1,p_2,\dots,p_k)$ and $\overline{q}=(q_1,q_2,\dots,q_k)$, all of them on the variables $x_1,\dots,x_n$ over some finite field $\...
Gadi A's user avatar
  • 19.4k
8 votes
2 answers
3k views

Factoring $X^{16}+X$ over $\mathbb{F}_2$

I just asked wolframalpha to factor $X^{16}+X$ over $\mathbb{F}_2$. The normal factorization is $$ X(X+1)(X^2-X+1)(X^4-X^3+X^2-X+1)(X^8+X^7-X^5-X^4-X^3+X+1) $$ and over $GF(2)$ it is $$ X(X+1)(X^2+...
Ryan's user avatar
  • 83
10 votes
3 answers
2k views

Intuition regarding Chevalley-Warning Theorem

Three versions of the theorem are stated on pages 1-2 in these notes by Pete L. Clark: http://alpha.math.uga.edu/~pete/4400ChevalleyWarning.pdf Could anyone offer some intuitive way to think about ...
Pandora's user avatar
  • 6,584
68 votes
2 answers
33k views

Number of monic irreducible polynomials of prime degree $p$ over finite fields

Suppose $F$ is a field s.t $\left|F\right|=q$. Take $p$ to be some prime. How many monic irreducible polynomials of degree $p$ do exist over $F$? Thanks!
IBS's user avatar
  • 4,215

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