O existenci a přibližném sestrojování charakteristických hodnot cyklických soustav operátorových rovnic
O integralnoj reprezentaciji linearnog operatora
-Topologies on the Test Function Algebra
O vlastních hodnotách diferenciálních rovnic
O спектре операторов в идеальных пространствах
Obere Schranken für Eigenwerte von Eigenwertaufgaben der Form (...2 I Â?...A Â? B) x = 0 . - Upper Bounds for Eigenvalues of Quadratic Eigenvalue Problem.
Observability properties of a semi-discrete 1d wave equation derived from a mixed finite element method on nonuniform meshes
The goal of this article is to analyze the observability properties for a space semi-discrete approximation scheme derived from a mixed finite element method of the 1d wave equation on nonuniform meshes. More precisely, we prove that observability properties hold uniformly with respect to the mesh-size under some assumptions, which, roughly, measures the lack of uniformity of the meshes, thus extending the work [Castro and Micu, Numer. Math.102 (2006) 413–462] to nonuniform meshes. Our results...
Odd anharmonic oscillators and shape resonances
Oka-analyticity of the essential spectrum
Old and new results on Allan's GB*-algebras
This is an expository paper on the importance and applications of GB*-algebras in the theory of unbounded operators, which is closely related to quantum field theory and quantum mechanics. After recalling the definition and the main examples of GB*-algebras we exhibit their most important properties. Then, through concrete examples we are led to a question concerning the structure of the completion of a given C*-algebra 𝓐₀[||·||₀], under a locally convex *-algebra topology τ, making the multiplication...
Omnipresent holomorphic operators and maximal cluster sets
On a binary relation between normal operators
The main goal of this paper is to clarify the antisymmetric nature of a binary relation ≪ which is defined for normal operators A and B by: A ≪ B if there exists an operator T such that for all Borel subset Δ of the complex plane ℂ, where and are spectral measures of A and B, respectively (the operators A and B are allowed to act in different complex Hilbert spaces). It is proved that if A ≪ B and B ≪ A, then A and B are unitarily equivalent, which shows that the relation ≪ is a partial order...
On a boundary value problem on the half-line for nonlinear two-dimensional delay differential systems
This article is concerned with a boundary value problem on the half-line for nonlinear two-dimensional delay differential systems. By the use of the Schauder-Tikhonov theorem, a result on the existence of solutions is obtained. Also, via the Banach contraction principle, another result concerning the existence and uniqueness of solutions is established. Moreover, these results are applied to the special case of ordinary differential systems and to a certain class of delay differential systems. Furthermore,...
On a Brezis-Nirenberg type problem.
On a cell decomposition for Hankel matrices and rational functions.
On a certain algorithm of eigenvalue localization for normal operators
On a certain approximation property for first-order abstract differential equations
On a certain class of always convergent sequences and the Rayleigh quotient iterations
On a certain class of nonstationary sequences in Hilbert space.
On a certain Volterra-Fredholm type integral equation.