On the diagonal of matrix transformations
On the differentiability of the norm in trace classes
On the differentiability of Urysohn and Nemyckii operators
On the dual of L(E, F).
On the Dunford-Pettis property
On the eigenvalues which express antieigenvalues.
On the equality between some classes of operators on Banach lattices
We establish some sufficient conditions under which the subspaces of Dunford-Pettis operators, of M-weakly compact operators, of L-weakly compact operators, of weakly compact operators, of semi-compact operators and of compact operators coincide and we give some consequences.
On the equivalence of differential operators of infinite order with constant coefficients
We investigate the conditions of equivalence of a differential operator of infinite order with constant coefficients to the operator of differentiation in one space of analytic functions. We also study the conditions of continuity of a differential operator of infinite order with variable coefficients in such space.
On the ergodic power function for invertible positive operators
On the essential order spectrum
On the essential spectra of matrix operators and applications.
On the Essential Spectrum of Schrödinger Operators with Spherically Symmetric Potentials.
On the Existence of Minimal Operators for Schrödinger-Type Differential Expressions.
On the existence of weak solutions for some quasilinear elliptic variational boundary value problems at resonance
On the extension of holomorphic functions on a locally convex space
On the extension of positive linear functionals.
On the fine spectra of some averaging operators.
On the fine spectrum of generalized upper double-band matrices over the sequence space
On the fine spectrum of the generalized difference operator over the sequence spaces and .
On the Fourier cosine—Kontorovich-Lebedev generalized convolution transforms
We deal with several classes of integral transformations of the form where is an operator. In case is the identity operator, we obtain several operator properties on with weights for a generalized operator related to the Fourier cosine and the Kontorovich-Lebedev integral transforms. For a class of differential operators of infinite order, we prove the unitary property of these transforms on and define the inversion formula. Further, for an other class of differential operators of finite...