Extension of Hardy–Littlewood–Sobolev Inequalities for Riesz Potentials on Hypergroups

Mediterranean Journal of Mathematics - Let p be a prime number, let G be a finite group, let N be a normal subgroup of G, and let $$\theta $$ be a G-invariant irreducible character of N. In Rizo (J...     

Riesz-Fejér Inequalities for Harmonic Functions

Potential Analysis - In this article, we prove the Riesz - Fejér inequality for complex-valued harmonic functions in the harmonic Hardy space hp for all p >?1. The result is sharp...     

Hardy–Littlewood–Sobolev Inequalities with the Fractional Poisson Kernel and Their Applications in PDEs

The purpose of this paper is five-fold. First, we employ the harmonic analysis techniques to establish the following Hardy–Littlewood–Sobolev inequality with the fractional Poisson kernel on the upper half space ■ where f ∈ L~p(?R_+~n), g ∈ Lq(R_+~n) and p, q'∈(1, +∞), 2 ≤α n satisfying (n-1)/np+1/q'+(2-α)/n= 1.Second, we utilize the technique combining the rearrangement inequality and Lorentz interpolation to show the attainability of best constant C_(n,α,p,q'). Third, we apply the regularity lifting method to obtain the smoothness of extremal functions of the above inequality under weaker assumptions. Furthermore,in light of the Pohozaev identity, we establish the sufficient and necessary condition for the existence of positive solutions to the integral system of the Euler–Lagrange equations associated with the extremals of the fractional Poisson kernel. Finally, by using the method of moving plane in integral forms, we prove that extremals of the Hardy–Littlewood–Sobolev inequality with the fractional Poisson kernel must be radially symmetric and decreasing about some point ξ_0 ∈ ?R_+~n. Our results proved in this paper play a crucial role in establishing the Stein–Weiss inequalities with the Poisson kernel in our subsequent paper.     

On the Generalization of Some Hermite–Hadamard Inequalities for Functions with Convex Absolute Values of the Second Derivatives Via Fractional Integrals

Ukrainian Mathematical Journal - We provide a unified approach to getting Hermite–Hadamard inequalities for functions with convex absolute values of the second derivatives via the...     

Hermite–Hadamard Type Inequalities for Functions Whose Derivatives are Operator Convex

In this paper, we shall offer two inequalities for differentiable mappings which the induced maps by them on the set of Hermitian operators are operator convex. we establish some estimates of the right hand side of a Hermite–Hadamard type inequality in which such functions are involved.     

Muckenhoupt Ap-properties of Distance Functions and Applications to Hardy–Sobolev -type Inequalities

Potential Analysis - Let X be a metric space equipped with a doubling measure. We consider weights w(x) = dist(x,E)?α, where E is a closed set in X and $alpha in mathbb {R}$ . We...     

Fractional Derivatives of Holomorphic Functions on Bounded Symmetric Domains of C~n

.9J.AnirnductionLetQbeaboundedsymmetricdomaininthecon1plexvectorspaceC",Oen,withBergman-Silovboundaryb,rthegroupofholomorphicautomorphismsofaandnitsisotropygroup.ItisknownthatDiscircularandstar-shapedwitl1respecttoOandbiscircular.ThegroupflistransitiveonbandbhasauniquenormalizedO-invariantmeasuredwithd(b)=1-Hua[2]constructedbygrouprepresentationtl1eoryasystem{%,}ofhomogeneouspolyno-l,J k-l\mails,k=O,l,..',v=l,..',))l*'nI*=('J k-l),coml>leteandorthogonalonnandortl1onor-malonb.ByH(Q)weden…     

Generalized Cranston–McConnell Inequalities for Discontinuous Superharmonic Functions

Let be an open set in R² with Green function G(x,y) for the Laplace equation. We give a generalization of the Cranston-McConnell inequality concerning the integrability of positive harmonic functions on .     

Caputo–Hadamard Fractional Derivatives of Variable Order

In this article, we present three types of Caputo–Hadamard derivatives of variable fractional order and study the relations between them. An approximation formula for each fractional operator, using integer-order derivatives only, is obtained and an estimation for the error is given. At the end, we compare the exact fractional derivative of a concrete example with some numerical approximations.     

Local Hardy–Littlewood maximal operator

In this article we define and investigate a local Hardy–Littlewood maximal operator in Euclidean spaces. It is proved that this operator satisfies weighted L ^p , p > 1, and weighted weak type (1,1) estimates with weight function ${w \in A^p_{\rm{loc}}}In this article we define and investigate a local Hardy–Littlewood maximal operator in Euclidean spaces. It is proved that this operator satisfies weighted L ^p , p > 1, and weighted weak type (1,1) estimates with weight function w ? A^p_loc{w \in A^p_{\rm{loc}}}, the class of local A _p weights which is larger than the Muckenhoupt A _p class. Also, the condition w ? A^p_loc{w \in A^p_{\rm{loc}}} turns out to be necessary for the weighted weak type (p,p), p ≥ 1, inequality to hold.     

Strong Hardy–Littlewood theorems for analytic functions and mappings of finite distortion

A formula is pointed out that explains why an analytic function often enjoys the same smoothness properties as its modulus. This is extended to quasiregular mappings and, mutatis mutandis, to mappings of finite distortion.Mathematics Subject Classification (1991): 30C65, 30D50, 30D55Supported in part by Grant 02-01-00267 from the Russian Foundation for Fundamental Research, DGICYT Grant BFM2002-04072-C02-01, CIRIT Grant 2001-SGR-00172, by the Ramón y Cajal program (Spain) and by the European Communitys Human Potential Program under contract HPRN-CT-2000-00116 (Analysis and Operators).     

Schwarz—Pick Inequalities for Derivatives of Arbitrary Order

Abstract. Let Ω and Π be two simply connected domains in the complex plane C which are not equal to the whole plane C and let λ _Ω and λ _Π denote the densities of the Poincare metric in Ω and Π , respectively. For f: Ω → Π analytic in Ω , inequalities of the type $$\frac{{|f^{(n)} (z)|}}{{n!}} \leqslant M_n (z,\Omega ,\Pi )\frac{{(\lambda _\Omega (z))^n }}{{\lambda _\Pi (f(z))}},z \in \Omega$$ are considered where M _n (z,Ω, Π) does not depend on f and represents the smallest value possible at this place. We prove that $$M_n (z,\Delta ,\Pi ) = (1 + |z|)^{n - 1}$$ if Δ is the unit disk and Π is a convex domain. This generalizes a result of St. Ruscheweyh. Furthermore, we show that $$C_n (\Omega ,\Pi ) = sup\left\{ {M_n (z,\Omega ,\Pi )|z \in \Omega } \right\} \leqslant 4^{n - 1}$$ holds for arbitrary simply connected domains whereas the inequality 2 ^n-1 ≤ C _n (Ω,Π) is proved only under some technical restrictions upon Ω and Π .     

Schwarz—Pick Inequalities for Derivatives of Arbitrary Order

   Abstract. Let Ω and Π be two simply connected domains in the complex plane C which are not equal to the whole plane C and let λ _Ω and λ _Π denote the densities of the Poincare metric in Ω and Π , respectively. For f: Ω → Π analytic in Ω , inequalities of the type

Sobolev and Hardy–Littlewood–Sobolev inequalities

This paper is devoted to improvements of Sobolev and Onofri inequalities. The additional terms involve the dual counterparts, i.e. Hardy–Littlewood–Sobolev type inequalities. The Onofri inequality is achieved as a limit case of Sobolev type inequalities. Then we focus our attention on the constants in our improved Sobolev inequalities, that can be estimated by completion of the square methods. Our estimates rely on nonlinear flows and spectral problems based on a linearization around optimal Aubin–Talenti functions.     

Euler–Lagrange Equations for Lagrangians Containing Complex-order Fractional Derivatives

Two variational problems of finding the Euler–Lagrange equations corresponding to Lagrangians containing fractional derivatives of real- and complex-order are considered. The first one is the unconstrained variational problem, while the second one is the fractional optimal control problem. The expansion formula for fractional derivatives of complex-order is derived in order to approximate the fractional derivative appearing in the Lagrangian. As a consequence, a sequence of approximated Euler–Lagrange equations is obtained. It is shown that the sequence of approximated Euler–Lagrange equations converges to the original one in the weak sense as well as that the sequence of the minimal values of approximated action integrals tends to the minimal value of the original one.     

Operators of Almost Hadamard Type and Hardy–Littlewood Operator in the Space of Entire Functions of Several Complex Variables

Mathematical Notes - Conditions (in particular, on the order of decrease of the coefficients) for the uniform Pringsheim convergence of double trigonometric series with rarely changing coefficients...