We study the Oseen problem with rotational effect in exterior three-dimensional domains. Using a variational approach we prove existence and uniqueness theorems in anisotropically weighted Sobolev spaces in the whole three-dimensional space. As the main tool we derive and apply an inequality of the FriedrichsPoincaré type and the theory of Calderon-Zygmund kernels in weighted spaces. For the ex...

This paper investigates the solvability, existence and uniqueness of solutions for a class of nonlinear fractional hybrid differential equations with Hilfer fractional derivative in a weighted normed space. The main result is proved by means of a fixed point theorem due to Dhage. An example to illustrate the results is included.

Abstract This work is to analyze a nonlocal dispersal model governed by Volterra type integral and two space integrals. A weighted included, an existence result of solutions for this proved. We assume suitably Hartman-type sign condition use sufficiently regular measure noncompactness. Finally, the degree theory referring condensing operators applied.

In the present paper, we study some approximation properties of the Szász type operators involving Charlier polynomials introduced by Varma and Taşdelen in 2012. First, we establish approximation in a Lipschitz type space and weighted approximation theorems for these operators. Then we obtain the error in the approximation of functions having derivatives of bounded variation.

We study the closure CSO of the set CSO of all complex symmetric operators on a separable, infinite-dimensional, complex Hilbert space. Among other things, we prove that every compact operator in CSO is complex symmetric. Using a construction of Kakutani as motivation, we also describe many properties of weighted shifts in CSO\CSO. In particular, we show that weighted shifts which demonstrate a...

In this paper a reduction and equivalence theorems for the boundedness of the composition of a quasilinear operator T with the Hardy and Copson operators in weighted Lebesgue spaces are proved. New equivalence theorems are obtained for the operator T to be bounded in weighted Lebesgue spaces restricted to the cones of monotone functions, which allow to change the cone of non-decreasing function...

The Bernstein approximation problem is to determine whether or not the space of all polynomials is dense in a given weighted C0-space on the real line. A theorem of de Branges characterizes non-density by existence of an entire function of Krein class being related with the weight in a certain way. An analogous result holds true for weighted sup-norm approximation by entire functions of exponen...

This study introduces (p,q)-hybrid Durrmeyer-Stancu type linear positive operators, which are generalized forms of q-hybrid Durrmeyer-Stancu-type operators and examines their approximation properties. The first modulus continuity on a finite interval is introduced using Peetre’s K-functional. Then, the weighted theorem in space provided Gadzhiev’s Korovkin-type theorem. Finally, these operators...