scholarly journals On some Gelfand-Mazur like theorems in Banach algebras

1979 ◽  
Vol 20 (2) ◽  
pp. 211-215 ◽  
Author(s):  
V.K. Srinivasan
Keyword(s):  
Banach Algebra ◽  
Integral Domain ◽  
Banach Algebras ◽  
Complex Field ◽  
Principal Ideal Domain ◽  
Locally Finite ◽  
Several Variables ◽  
Complex Banach Algebra ◽  
Noetherian Domain ◽  
Formal Power

The following Gelfand-Mazur like theorems are proved in this paper:(1) A complex Banach algebra which is locally finite, and which is also an integral domain, is isomorphic to the complex field .(2) A complex Banach algebra which is a noetherian domain is isomorphic to .(3) A complex Banach algebra which is a principal ideal domain is isomorphic to .An application is given to the algebra of all complex formal power series in several variables.

A theorem in Banach algebras and its applications

1979 ◽  
Vol 20 (2) ◽  
pp. 247-252 ◽  
Author(s):  
V.K. Srinivasan ◽  
Hu Shaing
Keyword(s):  
Banach Algebra ◽  
Principal Ideal ◽  
Banach Algebras ◽  
Negative Integer ◽  
Complex Field ◽  
Principal Ideal Domain ◽  
Bezout Domain ◽  
Ideal Domain ◽  
Complex Banach Algebra ◽  
Divisor Of Zero

If A is a complex Banach algebra which is also a Bezout domain, it is shown that for any prime p and a non-negative integer n, pn is not a topological divisor of zero. Using the above result it is shown that a complex Banach algebra which is a principal ideal domain is isomorphic to the complex field.

scholarly journals On some Gelfand-Mazur like theorems in Banach algebras: On some Gelfand-Mazur like theorems in P-normed algebras: Corrigenda

1981 ◽  
Vol 23 (3) ◽  
pp. 479-480
Author(s):  
V. K. Srinivasan
Keyword(s):  
Banach Algebra ◽  
Principal Ideal ◽  
Integral Domain ◽  
Finite Algebra ◽  
Banach Algebras ◽  
The Other ◽  
Closed Field ◽  
Finitely Generated ◽  
Ground Field ◽  
Locally Finite

REMARK 1. In my paper “On some Gelfand-Mazur like theorems in Banach algebras” [2], I stated as Theorem 3.1 the following result: If A is a complex Banach algebra, which is locally finite and if A is an integral domain then A is isomorphic to C. The proof given there is wrong. The mistake occurred when the principal ideal (h) was considered. Certainly (h) is finitely generated as an ideal, but not necessarily as an algebra. However thanks to the following theorem of Heinze [1], the stated Theorem 3.1 of my paper [2] is still correct. Heinze's results states: An associative locally finite algebra which is also an integral domain, over an algebraically closed field is isomorphic to the ground field. The other theorems stated in [2] are correct.

Banach algebras of power series

1974 ◽  
Vol 17 (3) ◽  
pp. 263-273 ◽  
Author(s):  
Richard J. Loy
Keyword(s):  
Power Series ◽  
Banach Algebra ◽  
Formal Power Series ◽  
Weak Topology ◽  
Present Author ◽  
Banach Algebras ◽  
Complex Field ◽  
Formal Power ◽  
Special Case

Let C[[t]] denote the algebra of all formal power series over the complex field C in a commutative indeterminate t with the weak topology determined by the projections pj: Σαiti ↦αj. A subalgebra A of C[[t]] is a Banach algebra of power series if it contains the polynomials and is a Banach algebra under a norm such that the inclusion map A ⊂ C[[t]] is continuous. Such algebras were first introduced in [13] when considering algebras with one generator, and studied, in a special case, in [23]. For a partial bibliography of their subsequent study and application see the references of [9] (note that the usage of the term Banach algebra of power series in [9] differs from that here), and also [2], [3], [11]. Indeed, an examination of their use in [11], under more general topological conditions than here, led the present author to the results of [14], [15], [16], [17].

scholarly journals Strictly real Banach algebras

1993 ◽  
Vol 47 (3) ◽  
pp. 505-519 ◽  
Author(s):  
John Boris Miller
Keyword(s):  
Banach Algebra ◽  
Uniqueness Theorem ◽  
Banach Algebras ◽  
Complex Algebra ◽  
Conjugation Operator ◽  
Complex Banach Algebra

A complex Banach algebra is a complexification of a real Banach algebra if and only if it carries a conjugation operator. We prove a uniqueness theorem concerning strictly real selfconjugate subalgebras of a given complex algebra. An example is given of a complex Banach algebra carrying two distinct but commuting conjugations, whose selfconjugate subalgebras are both strictly real. The class of strictly real Banach algebras is shown to be a variety, and the manner of their generation by suitable elements is proved. A corollary describes some strictly real subalgebras in Hermitian Banach star algebras, including C* algebras.

scholarly journals Completion of normed algebras of polunomials

1975 ◽  
Vol 20 (4) ◽  
pp. 504-510 ◽  
Author(s):  
H. G. Dales ◽  
J. P. McClure
Keyword(s):  
Power Series ◽  
Banach Algebra ◽  
Formal Power Series ◽  
Complex Field ◽  
Linear Functionals ◽  
Bounded Linear ◽  
One To One ◽  
Formal Power

Let P be the algebra of polynomials in one inderminate x over the complex field C. Suppose ∥ · ∥ is a norm on P such that the coefficient functionals cj: ∑αix1 → αj (j = 0,1,2,…) are all continuous with respect to ∥·∥, and Let K ⊂ C be the set of characters on P which are ∥·∥-continuous. then K is compact, C\K is connected, and 0∈K. K. Let A be the completion of P with respect to ∥·∥. Then A is a singly generated Banach algebra, with space of characters (homeomorphic with) K. The functionals cj have unique extensions to bounded linear functionals on A, and the map a →∑Ci(a)xi (a ∈ A) is a homomorphism from A onto an algebra of formal power series with coefficients in C. We say that A is an algebra of power series if this homomorphism is one-to-one, that is if a ∈ A and a≠O imply cj(a)≠ 0 for some j.

scholarly journals Continuity of derivations on topological algebras of power series

1969 ◽  
Vol 1 (3) ◽  
pp. 419-424 ◽  
Author(s):  
R.J. Loy
Keyword(s):  
Power Series ◽  
Banach Algebra ◽  
Formal Power Series ◽  
Topological Algebra ◽  
Fréchet Space ◽  
Frechet Space ◽  
Complex Field ◽  
Topological Algebras ◽  
Space Topology ◽  
Formal Power

Let A be an algebra of formal power series in one indeterminate over the complex field, D a derivation on A. It is shown that if A has a Fréchet space topology under which it is a topological algebra, then D is necessarily continuous provided the coordinate projections satisfy a certain equicontinuity condition. This condition is always satisfied if A is a Banach algebra and the projections are continuous. A second result is given, with weaker hypothesis on the projections and correspondingly weaker conclusion.

scholarly journals An order-preserving representation theorem for complex Banach algebras and some examples

1973 ◽  
Vol 14 (2) ◽  
pp. 128-135 ◽  
Author(s):  
A. C. Thompson ◽  
M. S. Vijayakumar
Keyword(s):  
Banach Algebra ◽  
Representation Theorem ◽  
Compact Hausdorff Space ◽  
Hausdorff Space ◽  
Banach Algebras ◽  
Order Structure ◽  
Commutative Case ◽  
Complex Matrices ◽  
Complex Banach Algebra

Let A be a complex Banach algebra with unit e of norm one. We show that A can be represented on a compact Hausdorff space ω which arises entirely out of the algebraic and norm structures of A. This space induces an order structure on A that is preserved by the representation. In the commutative case, ω is the spectrum of A, and we have a generalization of Gelfand's representation theorem for commutative complex Banach algebras with unit. Various aspects of this representation are illustrated by considering algebras of n × n complex matrices.

On S-GCD domains

2019 ◽  
Vol 18 (04) ◽  
pp. 1950067 ◽  
Author(s):  
D. D. Anderson ◽  
Ahmed Hamed ◽  
Muhammad Zafrullah
Keyword(s):  
Power Series ◽  
Formal Power Series ◽  
Integral Domain ◽  
Class Group ◽  
Nonzero Ideal ◽  
Noetherian Domain ◽  
Power Series Rings ◽  
Formal Power ◽  
Equivalent Conditions ◽  
Unit Formula

Let [Formula: see text] be a multiplicative set in an integral domain [Formula: see text]. A nonzero ideal [Formula: see text] of [Formula: see text] is said to be [Formula: see text]-[Formula: see text]-principal if there exist an [Formula: see text] and [Formula: see text] such that [Formula: see text]. Call [Formula: see text] an [Formula: see text]-GCD domain if each finitely generated nonzero ideal of [Formula: see text] is [Formula: see text]-[Formula: see text]-principal. This notion was introduced in [A. Hamed and S. Hizem, On the class group and [Formula: see text]-class group of formal power series rings, J. Pure Appl. Algebra 221 (2017) 2869–2879]. One aim of this paper is to characterize [Formula: see text]-GCD domains, giving several equivalent conditions and showing that if [Formula: see text] is an [Formula: see text]-GCD domain then [Formula: see text] is a GCD domain but not conversely. Also we prove that if [Formula: see text] is an [Formula: see text]-GCD [Formula: see text]-Noetherian domain such that every prime [Formula: see text]-ideal disjoint from [Formula: see text] is a [Formula: see text]-ideal, then [Formula: see text] is [Formula: see text]-factorial and we give an example of an [Formula: see text]-GCD [Formula: see text]-Noetherian domain which is not [Formula: see text]-factorial. We also consider polynomial and power series extensions of [Formula: see text]-GCD domains. We call [Formula: see text] a sublocally [Formula: see text]-GCD domain if [Formula: see text] is a [Formula: see text]-GCD domain for every non-unit [Formula: see text] and show, among other things, that a non-quasilocal sublocally [Formula: see text]-GCD domain is a generalized GCD domain (i.e. for all [Formula: see text] is invertible).

Commutative Banach Algebras with Idempotent Maximal Ideals

1969 ◽  
Vol 9 (3-4) ◽  
pp. 275-286 ◽  
Author(s):  
R. J. Loy
Keyword(s):  
Banach Algebra ◽  
Banach Algebras ◽  
Commutative Banach Algebra ◽  
Complex Field ◽  
Linear Combinations ◽  
Maximal Ideals ◽  
Commutative Banach Algebras ◽  
Finite Linear

Letbe a commutative Banach algebra over the complex fieldC,Man ideal of. Denote byM2the set of all finite linear combinations of products of elements fromM.Mwill be termed idempotent ifM2=M. The purpose of this paper is to investigate the structure of commutative Banach algebras in which all maximal ideals are idempotent.

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