In this paper, we study the maximal ideals in a commutative ring of bicomplex numbers and then describe algebra. We found that kernel nonzero multiplicative BC-linear functional Banach algebra need not be ideal. Finally, introduce notion division generalize Gelfand–Mazur theorem for

We give an exposition of Novodvorskii’s theorem in Banach algebra K-theory, asserting that the Gelfand transform for a commutative induces isomorphism topological K-theory.

Theorem 1.1. Let A be a semisimple complex Banach algebra with the following properties: (i) for every closed right ideal R in A, there exists a closed left ideal L such that R∩L= {0} and R+ L= A (each a∈ A can be written in the form a= a1 + a2 with a1 ∈ R, a2 ∈ L); (ii) if a,b in A are such that ab = ba= 0, then ‖a+ b‖2 = ‖a‖2 +‖b‖2. Then A is a commutative proper H∗-algebra [1]. It is easy to...

In this paper we prove that for a commutative character amenable Banach algebra A, if T : A → A is a multiplier then T has closed range if and only if T = BP = PB, where B ∈ M(A) is invertible and p ∈ M(A) is idempotent. By this result we characterize each multiplier with closed range on such Banach algebra (proposition 3.7), and so we get a necessary condition for character amenability of alge...

Commutative H *-algebra is characterized in terms of idempotents. Here we offer three characterizations. 1. Introduction. In the past, the author used commuting idempotents to characterize continuous functions defined on a certain space [3, 4]. For example , it was shown in [3] that a certain Banach algebra is isometrically isomorphic to the space C(S) of all continuous complex-valued functions...

We present here a quite unexpected result: Apart from already known commutative C∗-algebras generated by Toeplitz operators on the unit ball, there are many other Banach algebras generated by Toeplitz operators which are commutative on each weighted Bergman space. These last algebras are non conjugated via biholomorphisms of the unit ball, non of them is a C∗-algebra, and for n = 1 all of them ...

Let A be a complex, commutative unital Banach algebra. We introduce two notions of exponential reducibility of Banach algebra tuples and present an analogue to the Corach-Suárez result on the connection between reducibility in A and in C(M(A)). Our methods are of an analytical nature. Necessary and sufficient geometric/topological conditions are given for reducibility (respectively reducibility...

We study the differential equation $$\frac{\partial G}{\partial {{\bar{z}}}}=g$$ with an unbounded Banach-valued Bochner measurable function g on open unit disk $${\mathbb {D}}\subset {{\mathbb {C}}}$$ . prove that under some conditions growth and essential support of such has a bounded solution given by continuous linear operator. The obtained results are applicable to corona problem for algeb...

In the present paper, the concepts of module (uniform) approximate amenability and contractibility of Banach algebras that are modules over another Banach algebra, are introduced. The general theory is developed and some hereditary properties are given. In analogy with the Banach algebraic approximate amenability, it is shown that module approximate amenability and contractibility are the same ...