Questions tagged [polynomials]
Questions in which polynomials (single or several variables) play a key role. It is typically important that this tag is combined with other tags; polynomials appear in very different contexts. Please, use at least one of the top-level tags, such as nt.number-theory, co.combinatorics, ac.commutative-algebra, in addition to it. Also, note the more specific tags for some special types of polynomials, e.g., orthogonal-polynomials, symmetric-polynomials.
2,555
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Multiple zeta values related to fractional calculus and an Appell polynomial sequence
There is an Appell sequence of polynomials $p_n(z)$ related to an infinitesimal generator for one rep of the fractional calculus that have coefficients involving the Riemann zeta function values at ...
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1
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Elementary proof of growth estimate for a polynomial via size from its zero set
The paper Asymptotic properties of polynomials and algebraic functions of several variables by Gorin contains the following.
Lemma 3.1. Let $f\in \mathbb R[x_1,\dots,x_n]$. Suppose $f$ has a root in ...
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Asymptotics of perturbations of polynomial systems
Disclaimer: the following question is taken from math.SE. It relates to perturbation theory, and I'm interested in references (if any) that relate to the following problem:
Suppose we are given a ...
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1
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Algebraic solution for a system of algebraic equations?
How would one solve algebraically the following system of algebraic equations?
$$f(a,b):=a(1-b)+ab\frac a{a+b}.$$
$$u = f(a,b),\quad v = f(b,a).$$
Solve algebraically $(a,b)$ in terms of $(u,v)$
...
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1
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The locus of polynomials with specified root multiplicities
Let $\mathcal{P}_d\cong\mathbb{A}^d$ denote the set of monic degree $d$ polynomials defined over an algebraically closed field of characteristic $0$, where we identify $f(x)$ with its coefficients. ...
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1
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Homogeneous polynomial in 4 variable with non degenerate zero
I've got a very simple question about a homogenous polynomial, for which I cannot see neatly how to proceed (probably due to my limitations in algebraic geometry though). Any help would be greatly ...
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What are the algebraic steps to transform this expression? (Part of differential calculus) [closed]
sorry if this seems to be too easy for you, but I have struggled a lot with this expression and I don't get it how they got there:
How can $\sqrt{2x^2}$ become $4x^2$ ?
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Sign of an integer polynomial at a real algebraic number
Given $p\in\mathbb{Z}[x]$, assumed to have a real root, let $r$ be the largest real root of $p$. Now, given $f\in\mathbb{Z}[x]$ (without loss, of lesser degree than $p$), I would like to find out ...
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Given a polynomial constraint equation in $n$ variables, can one conclude that the sum of the variables is non-negative?
Currently I'm stuck as follows;
at least a positive proof if $n=3$ would be a great nice-to-have!
Consider real numbers $x_1,x_2,\dots,x_n$ satisfying
$$\prod^n_{k=1}\left(1-x_k^2\right)\:=\:\...
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Noncrossing partitions in Hopf algebras/monoids via compositional inversion
Partition polynomials constructed from the face structures of the associahedra (OEIS A133437) and permutahedra (A133314) comprise the antipodes/compositional inverses in a Faa-di-Bruno-type Hopf ...
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Monotonicity Theorem of inverse Kazhdan Lusztig polynomials
Let $P_{x,w}$ and $Q_{x,w}$ be the Kazhdan Lusztig polynomial and the inverse Kazhdan Lusztig polynomial of Coxeter group $W$, respectively. i.e., $\sum_{x\le y\le z}(-1)^{\ell(y)-\ell(x)}P_{x,y}(q)Q_{...
CommunityBot
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Progress on the result about montonicity of Kazhdan Lustzig polynomials
I am reading the paper Masato Kobayashi---Combinatorics on Bruhat Graphs and
Kazhdan-Lusztig Polynomials.
Let $P_{x,w}$ be the Kazhdan Lusztig polynomial of $W$.
There is a result about ...
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Polynomial defined recursively by a resultant
Cross posting from MSE.
Definition:
For any natural number $n\ge 3$, define the polynomial $P_{n}\left(x_1,x_2,...,x_{n-1},x_{n} \right)$, with indeterminates $x_{i}$, where $i\in\{1,2,...,n-1,n\}$, ...
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Irreducibility of a polynomial in two variables
Is the polynomial
$$P_n(x,y)=\displaystyle\sum_{a+b\leq n}x^ay^b$$
irreducible in $\mathbb Z[x,y]$?
For all $n\leq 500$ this is true (checked using Mathematica), so it is reasonable to presume ...
2
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On a special continuous extension of Sylvester's Theorem
Notations. Denote by $S^{-}\left\{a_0,a_1,\ldots,a_m\right\}$ the number of strict sign changes in the indicated sequence $\left\{a_j\right\}_{j=0}^{m}$ of real numbers (i.e., when counting the sign ...
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Showing equality of Eberlein polynomials
I have thought about the following question a long time and still got no progress.
Currently I am writing my master thesis about association schemes in combinatorics and need an equality which seems ...
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Criterion for parabolic Kazhdan-Lusztig polynomials to be monic power of $q$
Let $(W,S)$ be a Coxeter system, $I\subseteq S$, $W^I=\{w\in W: sw>w,\ \forall s\in I\}$, $P^{I,q}_{x,w}(q)$ be the parabolic Kazhdan-Lusztig polynomial of $W^I$ of type $q$.
In KAZHDAN–LUSZTIG ...
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Factorizing a bivariate polynomial
I have a bivariate polynomial for each $n=0,1,2...$
$$
f_n(x,y)=\sum _{k=0}^n \frac{(-1)^k}{2 k+1} \binom{n}{k} \left(x ^2-y ^2\right)^{2 n-2 k}\left([y ( x^2 -1) +x(1 -y^2 )]^{2 k+1}\\ \qquad\qquad\...
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The mysterious numbers $ \frac{13}{20} $ and $20$?
Let $g(x) = x^6 - 30 x $
Let $h(x) = x^6 $
Let $f(x) = x^2 - 2 $
Let $r$ be a reduced fraction $0 < \frac{p}{q} < 2 $ with integers $p,q > 1$
Let $f_{n+1}(x) = f(f_n(x)) = f_n(f(x)) , ...
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Process quicker than Fourier for squares of polynomials
FFT is a quick algorithm for multiplying two polynomials, but given it's a square (i.e. multiplying the polynomial with itself) can we find something better?
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About monotonicity of parabolic Kazhdan Lusztig polynomials
Let $W_I$ be the parabolic subgroup generated by $I$, ${}^IW$ be the set of minimal length right coset representative of $W_I$ in $W$, and $w_I$ be the longest element in $W_I$.
Let $P_{u,v}$ be the ...
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362
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Polynomials vanishing almost everywhere
Suppose that $f$ is a function from the prime-order field $\mathbb F_p$ to the field itself. Considering the evaluation map $P\mapsto P(x,f(x))$ and comparing the dimensions, it is easy to show that ...
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1
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Expanding into monomials
Given a multi-variable function $F$, denote the number of monomials by $N(F)$. For example, $N(x(x+y))=N(x^2+xy)=2$ and
$$
N(x(x+y)(x+y+z))=N(x^3+2x^2y+x^2z+xy^2+xyz)=5.
$$
Define the functions $f_n=...
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Aligned roots of irreducible polynomials
It is well known from this famous question that the roots of a random polynomial tend to be close to the unit circle. So I was wondering in a somewhat converse sense: for an irreducible polynomial, is ...
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Collinear Galois conjugates
This is inspired by this old question, which may provide a bit more background. But the two present questions seem somewhat more fundamental to me.
Let $p$ be an irreducible polynomial with integer ...
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Proving Vizing's and Brooks' theorem using the polynomial approach
It is known that the graph polynomial defined by $\prod_{i<j}(x_i-x_j)$ where the vertices $x_k\ \ , \ \ k=\{1,2\ldots,n\}$ are ordered with respect to some order; can be used to verify the proper ...
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Сomplement of the set of numbers of the form $ 4mn - m - n$?
Numbers of the form $4mn-m-n$ where $m,n\in\mathbb{Z}^+$ are
$$
A=\{2, 5, 8, 11, 12, 14, 17, 19, 20, 23, 26, 29, 30, 32, 33, 35, \ldots\}
$$
The set complement of the above set is
$$
B=\{1, 3, 4, 6, ...
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If two monic polynomials of $\mathbb{Z}_p[X]$ (p-adic integer coefficient) are relatively prime modulo p, then do they generate $\mathbb{Z}_p[X]$?
I'm currently reading a paper of Rene Schoof, and I got stuck in a line. And I'm trying to check the above sentence.
Although that seems to be elementary, I hope someone can give me a counterexample ...
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Chromatic number and graph polynomial
If $\prod_{i=1}^t x_i^{e_i}$ is a monomial, define
$$rad\biggl(\prod_{i=1}^t x_i^{e_i}\biggr)$$
to be the number of distinct (nonzero) values of $e_i$.
Now let $G$ be a simple graph with vertices ...
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Probability that a Random Monic Polynomial Has Few Real Zeros
In the paper https://arxiv.org/pdf/math/0006113.pdf, it is shown that the probability that a random polynomial $a_0 + a_1x + \cdots + a_n x^n$ has $o(\log n / \log\log n)$ real zeros is $n^{-b + o(1)}$...
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Factorization of polynomials in two variables
I have read, from the question
Irreducibility of polynomials in two variables, that all polynomials $f(x)-g(y)$, where $f, g$ are indecomposable polynomials, and there are no $a, b$ such that $g(ax+b)...
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3
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Can you efficiently solve a system of quadratic multivariate polynomials?
Given a system of 2nd-degree polynomials, $P=\{p_1,\dots,p_m\}$ where $p_i: \mathbb{R}^n \rightarrow \mathbb{R}$, can you efficiently find a common zero of all of these polynomials? In other words, ...
2
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1
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SDP representation of ideal polynomials for positivstellensatz refutations
If we want to certify the nonexistence of real solutions to a polynomial system of equations, i.e.
$$ S = \{ x\in \mathbb{R}^n \ | \ h_i (x) = 0, \ i=1,\dots,t \} = \emptyset, $$
we can produce a ...
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Example of applying real quantifier elimination algorithm for polynomials
Sorry if any of this is unclear, or doesn't make much sense, I'm still trying to figure it out, a practical example such as this would likely help me understand better than anything else. I have read ...
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Existence of algebraic integers with certain properties
Is the following statement true?
($\star$) Given integers $n > k > 0$, there exists a monic polynomial of degree $n$ with integer coefficients and constant term $\pm 1$, irreducible over $\...
CommunityBot
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Abel-Ruffini theorem for systems of polynomial equations
I know the Abel-Ruffini theorem, which states that a general polynomial equation in one variable with degree $\geq 5$ is not solvable in radicals. I wonder whether there is a similar result for ...
3
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0
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The rank of a special matrix
Suppose that $P$ is a polynomial of degree $d:=\deg P$ over a field $\mathbb F$ of zero characteristic, splitting completely into pairwise distinct linear factors, and $B,C\subset\mathbb F$ are sets ...
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1
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Integral zeros of the Newton polynomial
I'm trying to understand the following result;
Statement: A newton polynomial of the form
$$a_1 {x\choose c_1}+a_2{x\choose c_2}+a_3{x\choose c_3}+⋯+a_s{x\choose c_s},$$
where $0 ≤c_1<c_2<c_3&...
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0
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The graph polynomial of the Total Graph of a Graph
Consider the Total Graph ($T(G)$) of a graph $G$ with vertex set $V$ edge set $E=\{(u,v)\}$ with Line graph $L(G)$ and subdivision graph $S(G)$ (formed by putting a vertex in each edge of the original ...
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1
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Is OEIS A007018 really a subsequence of squarefree numbers?
A comment in A007018 a(n) = a(n-1)^2 + a(n-1), a(0)=1 claims
Subsequence of squarefree numbers (A005117). - Reinhard Zumkeller, Nov 15 2004
Is that really so?
As far as I know, it is an open ...
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1
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Forbidden polynomial identities by the abc conjecture
The Mason–Stothers theorem states
Let $a(t), b(t)$, and $c(t)$ be relatively prime polynomials such that $a + b = c$, with coefficients that are either real numbers or complex numbers. Then $\...
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4
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0
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212
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Divisibility of the derivatives of a polynomial
(Related to MO Problem 9924.)
Suppose that $f$ is a polynomial of degree $d>0$ over a field of zero characteristic.
It is not difficult to see that if $Q$ is yet another, non-constant polynomial, ...
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0
answers
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Concerning $(x,y) \mapsto (x^{\frac{n}{r}+1}y + A,\mu x^{-\frac{n}{r}}+B)$
Let $r \in \mathbb{N}-\{0\}$.
Commutative case:
Let $f : (x,y) \mapsto (p,q)$ be a map from $\mathbb{C}[x,y]$ to $\mathbb{C}[x^{1/r},x^{-1/r},y]$ satisfying the following two conditions:
(i) $\...
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3
votes
0
answers
241
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Interlacing sequences by polynomials?
Given $t=2^\ell$ where $\ell\in\mathbb N_{>0}$ and $M\in\mathbb Z$ and two sets of integers $\{a_1,\dots,a_t\}$ and $\{b_1,\dots,b_t\}$ with $0<a_1\leq \dots\leq a_t<M$ and $0<b_1\leq \...
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0
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93
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Can entropy of a network be written as a polynomial?
In my research, I met a problem here.
Consider a weighted graph Laplacian matrix
$$\mathcal{L}_w(\mathcal{G}) = DWD^T,$$ where $D$ is a incidence matrix and $W$ is diagonal with each diagonal ...
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5
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0
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193
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A non-commutative analog of a result concerning a Jacobian pair
Let $k$ be a field of characteristic zero and let $E=E(x,y) \in k[x,y]$.
Define $t_x(E)$ to be the maximum among $0$ and the $x$-degree of $E(x,0)$.
Similarly, define $t_y(E)$ to be the maximum among $...
- 2,783
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2
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954
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Polynomials that share at least one root
This is a generalization of an MSE question,
Polynomials that share at least one root.
Let $P(x)$ be a specific polynomial of degree $d$, with given
real coefficients $A_i$ ($A_d=1$), and real roots:
...
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1
vote
2
answers
286
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How many k-nomials of deg N divisible by X^16+x^12+x^5 +1 ? (Spectrum of CRC-16-CCITT erroc-correcting code ?)
Let us consider polynoms over $F_2$.
Consider the linear SUBSPACE of polynoms divisible by $x^{16}+x^{12}+x^5 +1$ and of degree less or equal $N$ (e.g. 40).
Question: How many k-nomials belong to ...
- 30.7k
13
votes
1
answer
522
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Are the logarithms of the integer polynomials discrete in $L^1$ of the unit circle?
Tautologically, the integer polynomials form a discrete set in $L^1$ of the unit circle. On the other hand, a set of logarithms ordered by norm becomes generally rather denser than the original set.
...
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0
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242
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Concerning certain Keller maps of $k[x,y]$
Let $k$ be a field of characteristic zero.
Let $(x,y) \mapsto (p,q) \in k[x,y]$ be a Keller map, namely, a $k$-algebra endomorphism of $k[x,y]$ with $\operatorname{Jac}(p,q):=p_xq_y-p_yq_x \in k-\{0\}...
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