Functional calculus and the Gelfand transformation
Functional calculus for a class of unbounded linear operators on some non-archimedean Banach spaces
This paper is mainly concerned with extensions of the so-called Vishik functional calculus for analytic bounded linear operators to a class of unbounded linear operators on . For that, our first task consists of introducing a new class of linear operators denoted and next we make extensive use of such a new class along with the concept of convergence in the sense of resolvents to construct a functional calculus for a large class of unbounded linear operators.
Functional calculus for generators of uniformly bounded holomorphic semigroups.
Functional compression-expansion fixed point theorem.
Functional Equations and Linear Transformations. IV. Interpolation.
Functional equations and linear transformations - permutability and inversion. (Short Communication).
Functional equations of delay type in spaces
Functional expansion-compression fixed point theorem of Leggett-Williams type.
Functional homomorphisms and dynamical systems.
Functional inequalities associated with additive mappings.
Functional model for commuting isometries
Functional models and asymptotically orthonormal sequences
Suppose is the Hardy space of the unit disc in the complex plane, while is an inner function. We give conditions for a sequence of normalized reproducing kernels in the model space to be asymptotically close to an orthonormal sequence. The completeness problem is also investigated.
Functionals on function and sequence spaces connected with the exponential stability of evolutionary processes
The exponential stability property of an evolutionary process is characterized in terms of the existence of some functionals on certain function spaces. Thus are generalized some well-known results obtained by Datko, Rolewicz, Littman and Van Neerven.
Functionals on sequence spaces connected with the exponential stability of evolutionary processes.
Functions of bounded variation on compact subsets of the plane
A major obstacle in extending the theory of well-bounded operators to cover operators whose spectrum is not necessarily real has been the lack of a suitable variation norm applicable to functions defined on an arbitrary nonempty compact subset σ of the plane. In this paper we define a new Banach algebra BV(σ) of functions of bounded variation on such a set and show that the function-theoretic properties of this algebra make it better suited to applications in spectral theory than those used previously....
Functions of least gradient and BV functions
Functions of operators and their commutators in perturbation theory
This paper shows some directions of perturbation theory for Lipschitz functions of selfadjoint and normal operators, without giving precise proofs. Some of the ideas discussed are explained informally or for the finite-dimensional case. Several unsolved problems are mentioned.
Functions with a Finite Number of Negative Squares on Semigroups.
Fundamental decay mode and asymptotic behaviour of positive semigroups
Fundamental operator-functions of degenerate differential and difference-differential operators in Banach spaces which have a Noether operator in the principal part.