Abstract Let ???? be a complex Hilbert space and A non-zero positive bounded linear operator on . The main aim of this paper is to discuss general method develop -operator seminorm -numerical radius inequalities semi-Hilbertian operators using the existing corresponding Among many other we prove that if S , T X ? ???? ( ), i.e., -adjoint exist, then <m:math xmlns:m="http://www.w3.org/1998/Math/...

We find the abnormal extremals on four-dimensional connected Lie groups with left-invariant sub-Finsler quasimetric defined by a seminorm two-dimensional subspace of algebra generating algebra. In terms structure constants and Minkowski support function unit ball which defines quasimetric, we establish criterion for strict abnormality these extremals.

We prove that, for any finite Blaschke product w=B(z) in the unit disk, corresponding Riemann surface over w–plane contains a one-sheeted disk of radius 0.5. Moreover, it with radial slit. apply this result to obtain universal lower estimate Bloch seminorm products.

Let us consider two compact connected and locally connected Hausdorff spaces M , N and two continuous functions φ : M → R, ψ : N → R . In this paper we introduce new pseudodistances between pairs (M,φ) and (N,ψ) associated with reparametrization invariant seminorms. We study the pseudodistance associated with the seminorm ‖φ‖ = maxφ − minφ, denoted by δΛ, and we find a sharp lower bound for it....

The paper deals with a singularly perturbed reaction diffusion model problem. The focus is on reliable a posteriori error estimators for the H1 seminorm that can be applied to anisotropic finite element meshes. A residual error estimator and a local problem error estimator are proposed and rigorously analysed. They are locally equivalent, and both bound the error reliably. Furthermore three mod...

We consider an optimal rearrangement maximization problem involving the fractional Laplace operator ( − Δ ) s , 0 < 1 and Gagliardo-Nirenberg seminorm [ u ] . prove existence of a maximizer, analyze its properties show that it satisfies unstable obstacle equation for some α > = χ { }

Abstract. Numerical solution of one-dimensional elliptic problems is investigated using an averaged discontinuous discretization. The corresponding numerical method can be performed using the favorable properties of the discontinuous Galerkin (dG) approach, while for the average an error estimation is obtained in the H-seminorm. We point out that this average can be regarded as a lower order mo...