On a question of A. Wilansky in normed algebras
On a theorem of Vesentini
Let 𝒜 be a Banach algebra over ℂ with unit 1 and 𝑓: ℂ → ℂ an entire function. Let 𝐟: 𝒜 → 𝒜 be defined by 𝐟(a) = 𝑓(a) (a ∈ 𝒜), where 𝑓(a) is given by the usual analytic calculus. The connections between the periods of 𝑓 and the periods of 𝐟 are settled by a theorem of E. Vesentini. We give a new proof of this theorem and investigate further properties of periods of 𝐟, for example in C*-algebras.
On A-convex and lm-convex algebra structures of a locally convex space
Given a locally convex space (V,Γ), we find (all) the multiplications π on V (associative or not) such that the algebra A ≡ (V,π,Γ) becomes (i) A-convex, (ii) lm-convex.
On ...-admissible Vector Space Topologies on C(X).
On applicability of the projection method to two-dimensional Toeplitz operators with measurable symbol.
On Arens-Michael algebras which do not have non-zero injective ⨶-modules
A certain class of Arens-Michael algebras having no non-zero injective topological ⨶-modules is introduced. This class is rather wide and contains, in particular, algebras of holomorphic functions on polydomains in , algebras of smooth functions on domains in , algebras of formal power series, and, more generally, any nuclear Fréchet-Arens-Michael algebra which has a free bimodule Koszul resolution.
On automatic continuity of 3-holomorphisms on Banach algebras.
On Banach algebras satisfying a spectral maximum principle
On barrelled topological modules.
On bounded Dual-valued derivations on certain Banach algebras
On Cental Morphisms
On certain products of Banach algebras with applications to harmonic analysis
Given Banach algebras A and B with spectrum σ(B) ≠ ∅, and given θ ∈ σ(B), we define a product , which is a strongly splitting Banach algebra extension of B by A. We obtain characterizations of bounded approximate identities, spectrum, topological center, minimal idempotents, and study the ideal structure of these products. By assuming B to be a Banach algebra in ₀(X) whose spectrum can be identified with X, we apply our results to harmonic analysis, and study the question of spectral synthesis,...
On certain quasi-complemented and complemented Banach algebras.
On character amenable Banach algebras
We obtain characterizations of left character amenable Banach algebras in terms of the existence of left ϕ-approximate diagonals and left ϕ-virtual diagonals. We introduce the left character amenability constant and find this constant for some Banach algebras. For all locally compact groups G, we show that the Fourier-Stieltjes algebra B(G) is C-character amenable with C < 2 if and only if G is compact. We prove that if A is a character amenable, reflexive, commutative Banach algebra, then A...
On circle-Exponential Topological Algebras
On Cohen's proof of the Factorization Theorem
Various proofs of the Factorization Theorem for representations of Banach algebras are compared with its original proof due to P. Cohen.
On (Co)homology of triangular Banach algebras
Suppose that A and B are unital Banach algebras with units and , respectively, M is a unital Banach A,B-module, is the triangular Banach algebra, X is a unital -bimodule, , , and . Applying two nice long exact sequences related to A, B, , X, , , and we establish some results on (co)homology of triangular Banach algebras.
On Continuity of Algebra Homomorphisms and Uniqueness of Metric Topology.
On derivations and crossed homomorphisms
We discuss some results about derivations and crossed homomorphisms arising in the context of locally compact groups and their group algebras, in particular, L¹(G), the von Neumann algebra VN(G) and actions of G on related algebras. We answer a question of Dales, Ghahramani, Grønbæk, showing that L¹(G) is always permanently weakly amenable. Then we show that for some classes of groups (e.g. IN-groups) the homology of L¹(G) with coefficients in VN(G) is trivial. But this is no longer true, in general,...
On differences of Riesz homomorphisms.