27 research outputs found
Convex-Cyclic Weighted Translations On Locally Compact Groups
A bounded linear operator on a Banach space is called a convex-cyclic
operator if there exists a vector such that the convex hull of
is dense in . In this paper, for given an aperiodic element
in a locally compact group , we give some sufficient conditions for a
weighted translation operator on
to be convex-cyclic. A necessary condition is also
studied. At the end, to explain the obtained results, some examples are given
On the Generalized Weighted Lebesgue Spaces of Locally Compact Groups
Let be a locally compact group with a fixed left Haar measure and Ω be a system of weights on . In this paper, we deal with locally convex space (,Ω) equipped with the locally convex topology generated by the family of norms (‖.‖,)∈Ω. We study various algebraic and topological properties of the locally convex space (,Ω). In particular, we characterize its dual space and show that it is a semireflexive space. Finally, we give some conditions under which (,Ω) with the convolution multiplication is a topological algebra and then characterize its closed ideals and its spectrum
Porosity of certain subsets of Lebesgue spaces on locally compact groups
Let be a locally compact group. In this paper, we show that if is a non-discrete locally compact group, and , then the set of all pairs for which is finite, forms a set of first category in .
10.1017/S000497271200094
Topologically transitive sequence of cosine operators on Orlicz spaces
For a Young function phi and a locally compact second countable group G, let L phi (G) denote the Orlicz space onG. In this paper, we present a necessary and sufficient condition for the topological transitivity of a sequence of cosine operators {Cn}n=1 infinity:={12(Tg,wn+Sg,wn)}n=1 infinity, defined on L phi (G). We investigate the conditions for a sequence of cosine operators to be topologically mixing. Further, we go on to prove a similar result for the direct sum of a sequence of cosine operators. Finally, we give an example of topologically transitive sequence of cosine operators
Bishop’s property (β) and weighted conditional type operators in k-quasi class A*n
An operator T is said to be k-quasi class A*n operator if T*ᵏ (|Tⁿ⁺¹|²/ⁿ⁺¹− |T*|² ) Tᵏ ≥ 0, for some positive integers n and k. In this paper, we prove that the k-quasi class A*n operators have Bishop, s property (β). Then, we give a necessary and sufficient condition for T ⊗S to be a k-quasi class A*n operator, whenever T and S are both non-zero operators. Moreover, it is shown that the Riesz idempotent for a non-zero isolated point λ0 of a k-quasi class A*n operator T say Rᵢ, is self-adjoint and ran(Rᵢ) = ker(T −λ₀) = ker(T −λ₀)*. Finally, as an application in the last section, a necessary and sufficient condition is given in such a way that the weighted conditional type operators on L² (Σ), defined by Tw,u(f) := wE(uf), belong to k-quasi- A*n class.Publisher's Versio
Porous sets and lineability of continuous functions on locally compact groups
Let G be a non-compact locally compact group. In this paper we study the size of the set {(f, g) is an element of A x B : f * g is well-defined on G} where A and B are normed spaces of continuous functions on G. We also consider the problem of the spaceability of the set
(C-0 (G) boolean AND (C-0(G) * C-0(G))) \ C-00 (G)
and (among other results) we show that, for G = R-n, the above set is strongly c-algebrable (and, therefore, algebrable and lineable) with respect to the convolution product