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3 votes
1 answer
190 views

Can the equation $1+z+z^q=z^n$ have multiple complex roots $z$?

It is proved here that the equation $1+z+z^2=z^n$ have no multiple complex roots. Q. Let us consider the equation $1+z+z^q=z^n$ where $q$ and $n$ are natural numbers with $1<q<n$. Any ...
ABB's user avatar
  • 4,058
3 votes
1 answer
137 views

Estimate the homogeneous components of a polynomial against its maximum

Let $P\equiv P(x) := \sum_{|\alpha|\leq m} c_\alpha\cdot x^\alpha$ be a real polynomial in $d$ variables of (total) degree $m$, where $d, m \in\mathbb{N}$ are fixed. (I.e., the above sum ranges over ...
fsp-b's user avatar
  • 463
1 vote
2 answers
588 views

Inequality between coefficients of a polynomial and its supremum

For $d, m \in\mathbb{N}$ fixed, let $P\equiv P(x) := \sum_{|\alpha|\leq m} c_\alpha\cdot x^\alpha$ be a real polynomial in $d$ variables of (total) degree $m$. (That is, the above sum ranges over all ...
fsp-b's user avatar
  • 463
3 votes
0 answers
233 views

Sequence unifomly bounded

Let $f(\lambda,z)$ be a continuous function on $\Bbb R^2$ such that I) For $n\in\Bbb N$ and $x\in\Bbb R^*_+$ we have : $f(n,x)=\cos(nx)+ x O\big(\frac{1}{n}\big)$ as $n\to\infty$ and $x\in[n^{-1}\...
Kacdima's user avatar
  • 81
8 votes
2 answers
887 views

Sum of the norm of polynomials

Let $\bar D$ denote the closed unit disc in the complex plane. Consider the function $f:\bar D\longrightarrow \mathbb{C}$, defined as $f(z)=z$ for all $z\in \bar D$. Let $n\in \mathbb{N}$. For $1\leq ...
User93709's user avatar
  • 355
1 vote
1 answer
137 views

When is a homogeneous polynomial an inner function on the unit torus?

What is the necessary and sufficient condition(s) for a homogeneous polynomial on torus(bidisk) to be an inner function? More precisely I want to know when absolute value of a homogeneous polynomial ...
Star.59's user avatar
  • 11
0 votes
1 answer
152 views

When can two Cauchy transforms intersect?

Given two polynomials $p$ and $q$ over reals and being guaranteed that both have all roots real I want to know if there is any characterization of the solutions of the equation $\frac{p'}{p} = \frac{q'...
user6818's user avatar
  • 1,893
2 votes
1 answer
850 views

Absolute convergence of logarithm of polynomial with positive coefficient ($\ln G(z) = \sum\limits_{i = 0}^\infty {{q_i}{z^i}} $)

Special problem: Let $G(z)$ be a probability generating function(pgf, the $z$ can be seen as real number or complex number), that is $$G(z) = \sum\limits_{i = 0}^\infty {{p_i}{z^i}} ,(\left| z \right|...