Gel’fond-Leont’ev generalized differentiation operators in spaces of type S

We study the properties of generalized type S spaces and Gel’fond-Leont’ev generalized differentiation operators of finite or infinite order over the spaces.     

Evolution equations with Gel’fond-Leont’ev generalized differentiation operators: II

We establish the solvability of the Cauchy problem for evolution equations with Gel’fond-Leont’ev generalized differentiation operators in spaces of the type W as well as in spaces of generalized functions (analytic functionals) of the type W′.     

On some properties of Gel’fond–Leont’ev generalized integration operators

In the class of linear continuous operators that act in the spaces of functions analytic in domains, we describe, in various forms, isomorphisms that commute with a power of the Gel’fond–Leont’ev generalized integration operator. We also obtain representations of all closed subspaces of the space of analytic functions that are invariant with respect to a power of the Gel’fond–Leont’ev generalized integration operator.     

Commutators of sublinear operators generated by Calderón-Zygmund operator on generalized weighted Morrey spaces

In this paper, the boundedness of a large class of sublinear commutator operators T _b generated by a Calderón-Zygmund type operator on a generalized weighted Morrey spaces \({M_{p,\varphi }}(w)\) with the weight function w belonging to Muckenhoupt’s class A _p is studied. When 1 < p < ∞ and b ∈ BMO, sufficient conditions on the pair (φ ₁, φ ₂) which ensure the boundedness of the operator T _b from \({M_{p,\varphi 1}}(w)\) to \({M_{p,\varphi 2}}(w)\) are found. In all cases the conditions for the boundedness of T _b are given in terms of Zygmund-type integral inequalities on (φ ₁, φ ₂), which do not require any assumption on monotonicity of φ ₁(x, r), φ ₂(x, r) in r. Then these results are applied to several particular operators such as the pseudo-differential operators, Littlewood-Paley operator, Marcinkiewicz operator and Bochner-Riesz operator.     

Sublinear operators with rough kernel generated by Calderón–Zygmund operators and their commutators on generalized Morrey spaces

The aim of this paper is to establish the boundedness of certain sublinear operators with rough kernel generated by Calderón–Zygmund operators and their commutators on generalized Morrey spaces under generic size conditions which are satisfied by most of the operators in harmonic analysis. The Marcinkiewicz operator which satisfies the conditions of these theorems can be considered as an example.     

Measures as convolution operators on H1 and Lip α

For any measure μ, let T_μ denote the operator defined as convolution by μ. The spectral theory of the operators T_μ is studied. We focus our attention on certain infinite Bernoulli convolutions of the form

, where the sequence {t_n} is subject to certain arithmetic constraints. It is shown that the corresponding convolution operators do not have “natural” spectra on the spaces H¹ and Lip α.     

Approximation of functions defined on the real axis by operators generated by λ-methods of summation of their Fourier integrals

We obtain asymptotic equalities for upper bounds of the deviations of operators generated by -methods (defined by a collection ={(·)} of functions continuous on [0; ) and depending on a real parameter ) on classes of (, )-differentiable functions defined on the real axis.__________Translated from Ukrainskyi Matematychnyi Zhurnal, Vol. 56, No. 9, pp. 1267–1280, September, 2004.     

Cosine families generated by second-order differential operators on W1,1(0, 1) with generalized Wentzell boundary conditions

Using the abstract framework [Bátkai, A. and Engel, K.-J., 2004, Abstract wave equations with generalized Wentzell boundary conditions. Journal of Differential Equations, 207, 1–20.] we show that certain second-order differential operators with generalized Wentzell boundary conditions generate cosine families and hence also analytic semigroups on W^1,1(0,1). This complements the main result [Favini, A., Ruiz Goldstein, G., Goldstein, J.A., Obrecht, E. and Romanelli, S., 2003, General Wentzell boundary conditions and analytic semigroups on W^{1, p} (0,1). Applicable Analysis, 82, 927–935.] on the generation of an analytic semigroup by the second derivative with generalized Wentzell boundary conditions on W^{1, p} (0,?1) for 1<p<∞.     

Functional characterization of Vasil’ev invariants

A cover of a manifold X is called an r-cover if any r points of X belong to a set in the cover. Let X and Y be two smooth manifolds, let Emb(X, Y) be the family of smooth embeddings X → Y, let M be an Abelian group, and let F: Emb(X, Y) → M be a functional. One says that the degree of F does not exceed r if for each finite open r-cover {U _i } _i∈I ; of X there exist functionals F _i : Emb(U _i , Y) → M, i ∈ I, such that for each a ∈ Emb(X, Y) one has

Generalized Fourier–Feynman transforms and generalized convolution products on Wiener space

In this paper we define a more general convolution product of functionals on Wiener space and develop the fundamental relationships between the generalized Fourier–Feynman transform and the convolution product.     

On a generalized Camassa–Holm equation with the flow generated by velocity and its gradient

In this paper, we consider a generalized Camassa–Holm equation with the flow generated by the vector field and its gradient. We first establish the local well-posedness of equation in the sense of Hadamard in both critical Besov spaces and supercritical Besov spaces. Then we gain a blow-up criterion. Under a sign condition we reach the sign-preserved property and a precise blow-up criterion. Applying this precise criterion we finally present two blow-up results and the precise blow-up rate for strong solutions to equation.     

Convergence of the Lavrent’ev method

The convergence of the Lavrent’ev method, which is a well-known regularization method for integral equations of the first kind, is analyzed as applied to equations with arbitrary linear bounded operators. A theorem concerning necessary and sufficient conditions for this convergence is proved. It is shown that these conditions are satisfied for two classes of integral equations that do not possess the properties required by the classical Lavrent’ev method.     

Spectral properties of generalized Cesàro operators on Hardy and weighted Bergman spaces

We investigate spectral properties of integral operators of the form

Hypercyclic and chaotic convolution operators associated with the Dunkl operator on <Emphasis Type=”Bold”>C</Emphasis>

Summary We show that there exist infinitely many positive integers m not of the form n-&ohgr;(n) for any positive integer n. Here, &ohgr;(n) stands for the number of distinct prime factors of n. A similar result holds with &ohgr;(n) replaced by the total number of prime factors of n (counting multiplicities), or by the number of divisors of n.     

Some trace inequalities of Čebyšev type for functions of operators in hilbert spaces

Some trace operator inequalities for synchronous functions that are related to the ?eby?ev inequality for sequences of real numbers are given.     

Generalized fractional maximal and integral operators on Orlicz and generalized Orlicz–Morrey spaces of the third kind

Positivity - In the present paper, we will characterize the boundedness of the generalized fractional integral operators $$I_{rho }$$ and the generalized fractional maximal operators $$M_{rho }$$...