On a differential inequality

Analysis ◽  
2008 ◽  
Vol 28 (3) ◽  
Author(s):  
Richard Fournier

We identify the extremal functions for a class of differential inequalities first introduced by Sanford S. Miller and P. T. Mocanu in 1978.

2005 ◽  
Vol 12 (2) ◽  
pp. 237-254
Author(s):  
Zdzisław Kamont ◽  
Adam Nadolski

Abstract We prove that a function of several variables satisfying a functional differential inequality with unbounded delay can be estimated by a solution of a suitable initial problem for an ordinary functional differential equation. As a consequence of the comparison theorem we obtain a Perron-type uniqueness result and a result on continuous dependence of solutions on given functions for partial functional differential equations with unbounded delay. We consider classical solutions on the Haar pyramid.


2021 ◽  
Vol 5 (1) ◽  
pp. 64-68
Author(s):  
Kuldeep Kaur Shergill ◽  
◽  
Sukhwinder Singh Billing ◽  

In the present paper, we define a class of non-Bazilevic functions in punctured unit disk and study a differential inequality to obtain certain new criteria for starlikeness of meromorphic functions.


2021 ◽  
Vol 5 (4) ◽  
pp. 228
Author(s):  
Ibtisam Aldawish ◽  
Rabha W. Ibrahim

The current study acts on the notion of quantum calculus together with a symmetric differential operator joining a special class of meromorphic multivalent functions in the puncher unit disk. We formulate a quantum symmetric differential operator and employ it to investigate the geometric properties of a class of meromorphic multivalent functions. We illustrate a set of differential inequalities based on the theory of subordination and superordination. In this real case study, we found the analytic solutions of q-differential equations. We indicate that the solutions are given in terms of confluent hypergeometric function of the second type and Laguerre polynomial.


Author(s):  
Damian Wiśniewski ◽  
Mariusz Bodzioch

AbstractWe consider the eigenvalue problem for the p(x)-Laplace-Beltrami operator on the unit sphere. We prove same integro-differential inequalities related to the smallest positive eigenvalue of this problem.


1989 ◽  
Vol 39 (2) ◽  
pp. 161-165
Author(s):  
Jurang Yan

A necessary and sufficient condition is obtained for a first order linear delay differential inequality to be oscillatory. Our main result improves and extends some known results.


Author(s):  
Sarra Benarab

We consider a two-point (including periodic) boundary value problem for the following system of differential equations that are not resolved with respect to the derivative of the desired function: f_i (t,x,x ̇,(x_i ) ̇ )=0,i= (1,n) ̅. Here, for any i= (1,n) ̅ the function f_i:[0,1]×R^n×R^n×R→R is measurable in the first argument, continuous in the last argument, right-continuous, and satisfies the special condition of monotonicity in each component of the second and third arguments. Assertions about the existence and two-sided estimates of solutions (of the type of Chaplygin’s theorem on differential inequality) are obtained. Conditions for the existence of the largest and the smallest (with respect to a special order) solution are also obtained. The study is based on results on abstract equations with mappings acting from a partially ordered space to an arbitrary set (see [S. Benarab, Z.T. Zhukovskaya, E.S. Zhukovskiy, S.E. Zhukovskiy. On functional and differential inequalities and their applications to control problems // Differential Equations, 2020, 56:11, 1440–1451]).


2004 ◽  
Vol 35 (1) ◽  
pp. 43-52 ◽  
Author(s):  
Peiguang Wang ◽  
Yonghong Wu

In this paper, we develop several new results related to the nonexistence criteria for eventually positive solutions of a class of second order neutral differential inequalities with distributed deviating arguments. The work generalizes various existing result.


2022 ◽  
Vol 7 (4) ◽  
pp. 5830-5843
Author(s):  
Ibtehal Alazman ◽  
◽  
Mohamed Jleli ◽  
Bessem Samet ◽  

<abstract><p>In this paper, we consider a two-times nonlinear fractional differential inequality involving both Hadamard-Caputo and Caputo fractional derivatives of different orders, with a singular potential term. We obtain sufficient criteria depending on the parameters of the problem, for which a global solution does not exist. Some examples are provided to support our main results.</p></abstract>


1996 ◽  
Vol 9 (4) ◽  
pp. 459-468 ◽  
Author(s):  
Vladimir V. Chernorutskii ◽  
Mark A. Krasnosel'skii

The theory of differential inequalities is extended to functional-differential equations with hysteresis nonlinearities. A key feature is the existence of a semiorder of the state space of nonlinearity and a special monotonicity of the righthand side of differential inequality.This article is dedicated to the memory of Roland L. Dobrushin.


2020 ◽  
Vol 20 (2) ◽  
pp. 385-397
Author(s):  
A. A. Kon’kov ◽  
A. E. Shishkov

AbstractWe obtain sufficient conditions for solutions of the mth-order differential inequality\sum_{|\alpha|=m}\partial^{\alpha}a_{\alpha}(x,u)\geq f(x)g(|u|)\quad\text{in % }B_{1}\setminus\{0\}to have a removable singularity at zero, where {a_{\alpha}}, f, and g are some functions, and {B_{1}=\{x:|x|<1\}} is a unit ball in {{\mathbb{R}}^{n}}. We show in some examples the sharpness of these conditions.


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