Results 1 to 10 of about 2,468 (122)

Finite-infinite range inequalities in the complex plane [PDF]

open access: yesInternational Journal of Mathematics and Mathematical Sciences, 1991
Let E⫅C be closed, ω be a suitable weight function on E, σ be a positive Borel measure on E. We discuss the conditions on ω and σ which ensure the existence of a fixed compact subset K of E with the following property.
H. N. Mhaskar
doaj   +2 more sources

Weighted polynomial inequalities in the complex plane

open access: yesJournal of Approximation Theory, 2012
zbMATH Open Web Interface contents unavailable due to conflicting licenses.
Vladimir V Andrievskii
exaly   +3 more sources

Differential subordinations and inequalities in the complex plane

open access: yesJournal of Differential Equations, 1987
Let f and F be analytic in the unit disc U. The function f is subordinate to F, written \(f\prec F\) or f(z)\(\prec F(z)\), if F is univalent, \(f(0)=F(0)\) and f(U)\(\subset F(U)\). The authors deal with second order differential subordinations of the form \((1)\quad \psi (p(z),zp'(z),z^ 2p''(z);z)\prec h(z),\) where \(\psi\) : \({\mathbb{C}}^ 3\times
Sanford Miller, Petru T Mocanu
exaly   +2 more sources

Second order differential inequalities in the complex plane

open access: yesJournal of Mathematical Analysis and Applications, 1978
AbstractLet w(z) be regular in the unit disk U and let h(r, s, t) be a complex function defined in a domain of C3. The authors determine conditions on h such that ¦ h(w(z), zw′(z), z2w″(z))¦ < 1 implies ¦ w(z)¦ < 1 and such that Re h(w(z), zw′(z), z2w″(z)) > 0 implies Re w(z) > 0. Applications of these results to univalent function theory, differential
Sanford Miller, Petru T Mocanu
exaly   +3 more sources

Hilbert transform in the complex plane and area inequalities for certain quadratic differentials. [PDF]

open access: yesMichigan Mathematical Journal, 1987
The author studies the Hilbert transform \[ T_ E(z)=- \frac{1}{\pi}\iint_{B}\frac{\chi_ E(\zeta)d\mu (\zeta)}{(z-\zeta)^ 2}, \] where \(\chi_ E\) is the characteristic function of a measurable set E in the (open) unit disk B and \(d\mu\) (\(\zeta)\) is Lebesgue measure.
Tadeusz Iwaniec
exaly   +4 more sources

Some Inequalities on Polynomials in the Complex Plane Concerning a Linear Differential Operator

open access: yesJournal of Mathematics
In this paper, we consider new extremal problems in the uniform norm between a univariate complex polynomial and its associated reciprocal polynomial involving a generalized B-operator.
Mayanglambam Singhajit Singh   +2 more
doaj   +2 more sources

Uniform and pointwise Bernstein-Walsh-type inequalities on a quasidisk in the complex plane [PDF]

open access: yesBulletin of the Belgian Mathematical Society - Simon Stevin, 2016
zbMATH Open Web Interface contents unavailable due to conflicting licenses.
Abdullayev, F.G., Özkartepe, P.
exaly   +4 more sources

Carathéodory properties of Gaussian hypergeometric function associated with differential inequalities in the complex plane

open access: yesAIMS Mathematics, 2021
<abstract><p>The results presented in this paper highlight the property of the Gaussian hypergeometric function to be a Carathéodory function and refer to certain differential inequalities interpreted in form of inclusion relations for subsets of the complex plane using the means of the theory of differential superordination and the method ...
Georgia Irina Oros
exaly   +4 more sources

Bernstein-Walsh-type inequalities for derivatives of algebraic polynomials on the regions of complex plane

open access: yesTurkish Journal of Mathematics, 2022
In this paper, we study Bernstein-Walsh-type estimates for the derivatives of an arbitrary algebraic polynomial on some general regions of the complex plane.
Fahreddin Abdullayev
exaly   +3 more sources

Inequalities Involving Weighted Means in a Disc of the Complex Plane

open access: yesJournal of Mathematical Analysis and Applications, 2000
For complex numbers \(z_j\), \(j=1,2,\dots,n\), such that \(|z_j-1|\leq r\), \(r\in(0,1)\), the author considers the weighted means: \(H:= (\sum^n_{j=1} \lambda_jz_j^{-1})\), \(G:=\prod^n_{j=1} z_j^{\lambda_j}\) and \(A: =\sum^n_{j=1} \lambda_jz_j\), where \(\lambda_j>0\), \(\lambda_1+ \cdots+ \lambda_n =1\). Among other results, he proves: Theorem 1. \
exaly   +2 more sources

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