A remark on the differential equations on the sphere
A remark on the local Lipschitz continuity of vector hysteresis operators
It is known that the vector stop operator with a convex closed characteristic of class is locally Lipschitz continuous in the space of absolutely continuous functions if the unit outward normal mapping is Lipschitz continuous on the boundary of . We prove that in the regular case, this condition is also necessary.
A remark on the minimal displacement problem in spaces uniformly rotund in every direction
We give an example of uniformly rotund in every direction space for which the minimal displacement characteristic is maximal.
A remark on the multipliers on spaces of Weak Products of functions
If H denotes a Hilbert space of analytic functions on a region Ω ⊆ Cd , then the weak product is defined by [...] We prove that if H is a first order holomorphic Besov Hilbert space on the unit ball of Cd , then the multiplier algebras of H and of H ⊙ H coincide.
A remark on the range of elementary operators
Let denote the algebra of all bounded linear operators on a separable infinite dimensional complex Hilbert space into itself. Given , we define the elementary operator by . In this paper we study the class of operators which have the following property: implies for all trace class operators . Such operators are termed generalized quasi-adjoints. The main result is the equivalence between this character and the fact that the ultraweak closure of the range of is closed under taking...
A remark on the weighted averages for superadditive processes.
A Remark on Two Hilbert Space Scattering Theory.
A remark to a multipoint boundary value problem
A remark to a paper of Janas “Toeplitz operators related to certain domains in ”
A remark to the paper “On condensing discrete dynamical systems”
In the paper a new proof of Lemma 11 in the above-mentioned paper is given. Its original proof was based on Theorem 3 which has been shown to be incorrect.
A renorming of , rare but with the fixed-point property.
A representation formula for strongly continuous cosine families. (Short Communication).
A representation formula for strongly continuous cosine families.
A representation theorem for operators on a space of interval functions.
A Reproducing Kernel and Toeplitz Operators in the Quantum Plane
We define and analyze Toeplitz operators whose symbols are the elements of the complex quantum plane, a non-commutative, infinite dimensional algebra. In particular, the symbols do not come from an algebra of functions. The process of forming operators from non-commuting symbols can be considered as a second quantization. To do this we construct a reproducing kernel associated with the quantum plane. We also discuss the commutation relations of creation and annihilation operators which are defined...
A resolution of Simon's maximal monotonicity problem.
A resolvent condition implying power boundedness
The Ritt and Kreiss resolvent conditions are related to the behaviour of the powers and their various means. In particular, it is shown that the Ritt condition implies the power boundedness. This improves the Nevanlinna characterization of the sublinear decay of the differences of the consecutive powers in the Esterle-Katznelson-Tzafriri theorem, and actually characterizes the analytic Ritt condition by two geometric properties of the powers.
A result on best approximation in -normed spaces
We study best approximation in -normed spaces via a general common fixed point principle. Our results unify and extend some known results of Carbone [ca:pt], Dotson [do:bs], Jungck and Sessa [ju:at], Singh [si:at] and many of others.
A result on segmenting Jungck–Mann iterates
In this paper, following the concepts in [5, 7], we shall establish a convergence result in a uniformly convex Banach space using the Jungck–Mann iteration process introduced by Singh et al [13] and a certain general contractive condition. The authors of [13] established various stability results for a pair of nonself-mappings for both Jungck and Jungck–Mann iteration processes. Our result is a generalization and extension of that of [7] and its corollaries. It is also an improvement on the result...
A result on the well posedness of the Cauchy problem for a class of hyperbolic operators with double characteristics