Gelfand representation of Banach modules

Joseph W. Kitchen; David A. Robbins

  • Publisher: Instytut Matematyczny Polskiej Akademi Nauk(Warszawa), 1982

Abstract

top
PrefaceLet A be a commutative Banach algebra with maximal ideal space ∆ and let ^: A → C₀(∆) be the Gelfand representation of A. If M is a Banach module over A, then a bounded linear map φ: M → M₀, will be called a representation of M of Gelfund type if M₀ is a Banach module over C₀(∆) and φ is ^-linear in the sense that φ(ax) = âφ(x) for all a ∈ A and x ∈ M. Two such representations have been studied previously. In [50] and [51] Robbins describes such a representation in which M₀, is taken to be a space of continuous complex-valued functions. Varela and Hofmann have considered the special case in which A is a commutative C*-algebra with identity and in that case they describe a very different type of representation in which M₀ = Γ(π),the space of continuous sections of a bundle of Banach spaces π : E → ∆. The present paper generalizes considerably the sectional representation studied by Varela and Hofmann and shows its "equivalence" to the representation studied by Robbins. For a very large class of Banach modules (M, A), including essential modules over Banach algebras with bounded approximate identities, it is shown that there is a bundle of Banach spaces π : E → ∆ and a representation ^: M → Γ₀(π) which is not only of Gelfand type, but is universal with respect to all sectional representations of Gelfand type. This representation, which is unique up to isomorphism, is called the Gelfand representation of the module. Its basic properties are developed in the second section of the paper. Flanking this section are a preliminary section concerning bundles and a section devoted to examples. The final section explores functorially the relationships between Banach modules, bundles of Banach spaces, and their morphisms.

How to cite

top

Joseph W. Kitchen, and David A. Robbins. Gelfand representation of Banach modules. Warszawa: Instytut Matematyczny Polskiej Akademi Nauk, 1982. <http://eudml.org/doc/268433>.

@book{JosephW1982,
abstract = {PrefaceLet A be a commutative Banach algebra with maximal ideal space ∆ and let ^: A → C₀(∆) be the Gelfand representation of A. If M is a Banach module over A, then a bounded linear map φ: M → M₀, will be called a representation of M of Gelfund type if M₀ is a Banach module over C₀(∆) and φ is ^-linear in the sense that φ(ax) = âφ(x) for all a ∈ A and x ∈ M. Two such representations have been studied previously. In [50] and [51] Robbins describes such a representation in which M₀, is taken to be a space of continuous complex-valued functions. Varela and Hofmann have considered the special case in which A is a commutative C*-algebra with identity and in that case they describe a very different type of representation in which M₀ = Γ(π),the space of continuous sections of a bundle of Banach spaces π : E → ∆. The present paper generalizes considerably the sectional representation studied by Varela and Hofmann and shows its "equivalence" to the representation studied by Robbins. For a very large class of Banach modules (M, A), including essential modules over Banach algebras with bounded approximate identities, it is shown that there is a bundle of Banach spaces π : E → ∆ and a representation ^: M → Γ₀(π) which is not only of Gelfand type, but is universal with respect to all sectional representations of Gelfand type. This representation, which is unique up to isomorphism, is called the Gelfand representation of the module. Its basic properties are developed in the second section of the paper. Flanking this section are a preliminary section concerning bundles and a section devoted to examples. The final section explores functorially the relationships between Banach modules, bundles of Banach spaces, and their morphisms.},
author = {Joseph W. Kitchen, David A. Robbins},
keywords = {Banach algebra; Banach module; bundle of Banach spaces; canonical bundle; section; sectional representation; Gelfand representation; space of bounded sections; sheaf},
language = {eng},
location = {Warszawa},
publisher = {Instytut Matematyczny Polskiej Akademi Nauk},
title = {Gelfand representation of Banach modules},
url = {http://eudml.org/doc/268433},
year = {1982},
}

TY - BOOK
AU - Joseph W. Kitchen
AU - David A. Robbins
TI - Gelfand representation of Banach modules
PY - 1982
CY - Warszawa
PB - Instytut Matematyczny Polskiej Akademi Nauk
AB - PrefaceLet A be a commutative Banach algebra with maximal ideal space ∆ and let ^: A → C₀(∆) be the Gelfand representation of A. If M is a Banach module over A, then a bounded linear map φ: M → M₀, will be called a representation of M of Gelfund type if M₀ is a Banach module over C₀(∆) and φ is ^-linear in the sense that φ(ax) = âφ(x) for all a ∈ A and x ∈ M. Two such representations have been studied previously. In [50] and [51] Robbins describes such a representation in which M₀, is taken to be a space of continuous complex-valued functions. Varela and Hofmann have considered the special case in which A is a commutative C*-algebra with identity and in that case they describe a very different type of representation in which M₀ = Γ(π),the space of continuous sections of a bundle of Banach spaces π : E → ∆. The present paper generalizes considerably the sectional representation studied by Varela and Hofmann and shows its "equivalence" to the representation studied by Robbins. For a very large class of Banach modules (M, A), including essential modules over Banach algebras with bounded approximate identities, it is shown that there is a bundle of Banach spaces π : E → ∆ and a representation ^: M → Γ₀(π) which is not only of Gelfand type, but is universal with respect to all sectional representations of Gelfand type. This representation, which is unique up to isomorphism, is called the Gelfand representation of the module. Its basic properties are developed in the second section of the paper. Flanking this section are a preliminary section concerning bundles and a section devoted to examples. The final section explores functorially the relationships between Banach modules, bundles of Banach spaces, and their morphisms.
LA - eng
KW - Banach algebra; Banach module; bundle of Banach spaces; canonical bundle; section; sectional representation; Gelfand representation; space of bounded sections; sheaf
UR - http://eudml.org/doc/268433
ER -

NotesEmbed ?

top

You must be logged in to post comments.

To embed these notes on your page include the following JavaScript code on your page where you want the notes to appear.

Only the controls for the widget will be shown in your chosen language. Notes will be shown in their authored language.

Tells the widget how many notes to show per page. You can cycle through additional notes using the next and previous controls.

    
                

Note: Best practice suggests putting the JavaScript code just before the closing </body> tag.