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6 votes
0 answers
114 views

A question about the span of a sequence of polynomials satisfying a linear recurrence

Let F be a finite field and A(n) in F[t], n in N, be defined by a linear recurrence with coefficients in F[t], together with initial conditions. Is there a decision procedure for determining whether ...
paul Monsky's user avatar
  • 5,422
4 votes
0 answers
833 views

When spreading out a scheme, does the choice of max ideal matter?

I'm looking at Serre's paper How to use Finite Fields for Problems Concerning Infinite Fields. Specifically I'm trying to use the techniques in the proof of Theorem 1.2 to write out the details of the ...
Mike Pierce's user avatar
  • 1,161
4 votes
0 answers
191 views

Chevalley-Warning for finite rings: the degree of a non-polynomial

$\def\F{\mathbb F}$ $\def\Z{\mathbb Z}$ One reason that Chevalley-Warning theorem is that amazingly useful is the fact that for a finite field $\F$, any function from $\F^n$ to $\F$ is a polynomial. ...
Seva's user avatar
  • 23k
4 votes
0 answers
261 views

When is a given polynomial a square of another polynomial?

I meet a problem in which I hope to show a special polynomial is not a square of another polynomial. More precisely, let's consider the polynomial $f(x):= 1-x+2bx^n-2bx^{n+1}-b^2x^{2n-1}+2b^2x^{2n}-b^...
Joy-Joy's user avatar
  • 271
3 votes
0 answers
324 views

Roots of polynomials over $\mathbb{Z}/p^k\mathbb{Z}$

Over a finite field, such as $\mathbb{Z}/p\mathbb{Z}$, the number of roots of a polynomial is no larger than the degree. I'm interested in how does this generalize to $\mathbb{Z}/p^k\mathbb{Z}$. I'm ...
user122270's user avatar
3 votes
0 answers
320 views

When does composing polynomials reduce the degree?

Let $\mathbb{F}$ be the field of size 2. For a function $f : \mathbb{F}^n \to \mathbb{F}$, let $d(f)$ be the smallest integer such that there exists a degree-$d(f)$, $n$-variate, multilinear ...
user94741's user avatar
2 votes
0 answers
121 views

When $\gcd(P(x),Q(x))\bmod R(x)=\gcd(P(x) \bmod R(x),Q(x) \bmod R(x))$?

Let's $P,Q\in\mathbb K[x]$, with $\mathbb K$ a finite field. On what necessary and sufficient condition on $R \in \mathbb K[x]$ is it : $\gcd(P(x),Q(x))\bmod R(x)=\gcd(P(x) \bmod R(x),Q(x) \bmod R(x))...
Dattier's user avatar
  • 4,074
2 votes
0 answers
67 views

Partitioning a given set into root set of two polynomials or non zero set of two polynomials simultaneously

Let $p,q$ be two prime numbers and let $p<q.$ Also let, $\mathbb{Z}_p$ and $\mathbb{Z}_q$ denote the fields formed by integers modulo $p$ and modulo $q$ respectively (with respect to the modulo $p$ ...
Aditya Guha Roy's user avatar
1 vote
0 answers
88 views

When does sum of algebraically independent polynomial become dependent?

Given $f_1,...,f_n \in \mathbb{F}[x_1,...,x_n]$ where $f_n = g + h$. Suppose the sets $\{ f_1,...,f_{n-1},g \}$ and $\{ f_1,...,f_{n-1},h \}$ are algebraically independent then is there a ...
Rishabh Kothary's user avatar
1 vote
0 answers
1k views

Are the integers a vector space or algebra over "some" field or over "some" ring?

Every vector $v$ in a finite-dimensional vector space space $V$ of dimension $n$ over a field $F$ has a unique representation in terms of a basis ${\frak B} \subseteq V$, where a basis for $V$ is a ...
étale-cohomology's user avatar
0 votes
0 answers
53 views

A question on bounding the size of the polynomial

Suppose we are given the following n polynomials in $\bar{\mathbb{F}}_2[x_1,...,x_n]$: $f_1 = x_1 + x_n^2$ $f_2 = x_2 + x_1^2$ $\cdot$ $\cdot$ $f_{n-3} = x_{n-3} + x_{n-4}^2$ $f_{n-2} = x_{n-2} + x_{n-...
Rishabh Kothary's user avatar
0 votes
0 answers
97 views

Algebraic independence and substitution for quadratics

Let $f_{1},...,f_{n-1} \in \mathbb{F}[x_1,...,x_n]$ such that $\{ f_1,..., f_{n-1},x_n \}$ is algebraically independent over $\mathbb{F}$. Let $G \in \mathbb{F}[x_1,...,x_n,y_1,...,y_{n-1}]\...
Rishabh Kothary's user avatar
0 votes
0 answers
113 views

Relation between minimality and algebraic independence for binomials?

$\DeclareMathOperator\supp{supp}$Given $f_1,...,f_n \in \mathbb{F}[x_1,...,x_n]$ such that $f_1 = x_1 + q_1$ $f_2 = x_2 + q_2$ $\cdot \cdot \cdot$ $f_{n-1} = x_{n-1} + q_{n-1}$ $f_{n} = q_n$ such that ...
Rishabh Kothary's user avatar
0 votes
0 answers
184 views

Degree 6 Galois extension over $\mathbb{Q} $

Let L be the splitting field of $ x^3- 2$ over $ \mathbb{Q}$. Then $ G=\operatorname{Gal}(L/K) \cong S_3$. Let $\sigma\in G$ such that the fixed field of $ \sigma$ is $\mathbb{Q}(2^{1/3})$. Let $x,y\...
Sky's user avatar
  • 923
0 votes
0 answers
117 views

A question on a system of quadratic polynomials

Consider the following system of quadratic polynomials $f_1,...,f_n \in \bar{\mathbb{F}}_2[x_1,....,x_n]$ : $f_1 (\bar{x}) = x_1 + x_n^2 + q_1$ $f_i(\bar{x}) = x_i + q_i$ for $i \in \{2,...,n-1 \}$ $...
Rishabh Kothary's user avatar
0 votes
0 answers
89 views

Representing an $m$ dimensional quadratic polynomial as a polynomial on $\mathbb F_{q^m}$

We can represent $\mathbb{F}_{q^m}$ as $\mathbb{F}_q[\alpha]$ where $\alpha$ is root of an irreducible $m$-degree polynomial on $\mathbb{F}_q$. By sending $\sum_{i=0}^{m-1} c_i\alpha^i \mapsto (c_{m-1}...
user's user avatar
  • 1
0 votes
0 answers
82 views

Fast double exponentiation in finite fields

Let $p$ be a prime, and let $\mathbb{F}_p$ be the finite field with $p$ elements. Let $a$ be a non-zero element of $\mathbb{F}_p$. Can we quickly evaluate $a^{2^r} \mod{p}$? Using repeated squaring, ...
Gautam's user avatar
  • 1,703