Banach spaces with small Calkin algebras

Manuel González

Banach Center Publications (2007)

  • Volume: 75, Issue: 1, page 159-170
  • ISSN: 0137-6934

Abstract

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Let X be a Banach space. Let 𝓐(X) be a closed ideal in the algebra ℒ(X) of the operators acting on X. We say that ℒ(X)/𝓐(X) is a Calkin algebra whenever the Fredholm operators on X coincide with the operators whose class in ℒ(X)/𝓐(X) is invertible. Among other examples, we have the cases in which 𝓐(X) is the ideal of compact, strictly singular, strictly cosingular and inessential operators, and some other ideals introduced as perturbation classes in Fredholm theory. Our aim is to present some classes of Banach spaces and some concrete examples of Banach spaces for which some of their Calkin algebras are "small" in some sense: finite dimensional, commutative, etc. The first example of such a Banach space was constructed around 1990. However, at this moment there is a great variety of examples of spaces of this kind, which provides interesting examples and counterexamples of operators. Moreover, the methods and techniques of operator theory have been found to be useful in the study of these spaces.

How to cite

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Manuel González. "Banach spaces with small Calkin algebras." Banach Center Publications 75.1 (2007): 159-170. <http://eudml.org/doc/282332>.

@article{ManuelGonzález2007,
abstract = {Let X be a Banach space. Let 𝓐(X) be a closed ideal in the algebra ℒ(X) of the operators acting on X. We say that ℒ(X)/𝓐(X) is a Calkin algebra whenever the Fredholm operators on X coincide with the operators whose class in ℒ(X)/𝓐(X) is invertible. Among other examples, we have the cases in which 𝓐(X) is the ideal of compact, strictly singular, strictly cosingular and inessential operators, and some other ideals introduced as perturbation classes in Fredholm theory. Our aim is to present some classes of Banach spaces and some concrete examples of Banach spaces for which some of their Calkin algebras are "small" in some sense: finite dimensional, commutative, etc. The first example of such a Banach space was constructed around 1990. However, at this moment there is a great variety of examples of spaces of this kind, which provides interesting examples and counterexamples of operators. Moreover, the methods and techniques of operator theory have been found to be useful in the study of these spaces.},
author = {Manuel González},
journal = {Banach Center Publications},
keywords = {Calkin algebra; essential spectrum; semi-Fredholm operator; hereditarily indecomposable Banach space},
language = {eng},
number = {1},
pages = {159-170},
title = {Banach spaces with small Calkin algebras},
url = {http://eudml.org/doc/282332},
volume = {75},
year = {2007},
}

TY - JOUR
AU - Manuel González
TI - Banach spaces with small Calkin algebras
JO - Banach Center Publications
PY - 2007
VL - 75
IS - 1
SP - 159
EP - 170
AB - Let X be a Banach space. Let 𝓐(X) be a closed ideal in the algebra ℒ(X) of the operators acting on X. We say that ℒ(X)/𝓐(X) is a Calkin algebra whenever the Fredholm operators on X coincide with the operators whose class in ℒ(X)/𝓐(X) is invertible. Among other examples, we have the cases in which 𝓐(X) is the ideal of compact, strictly singular, strictly cosingular and inessential operators, and some other ideals introduced as perturbation classes in Fredholm theory. Our aim is to present some classes of Banach spaces and some concrete examples of Banach spaces for which some of their Calkin algebras are "small" in some sense: finite dimensional, commutative, etc. The first example of such a Banach space was constructed around 1990. However, at this moment there is a great variety of examples of spaces of this kind, which provides interesting examples and counterexamples of operators. Moreover, the methods and techniques of operator theory have been found to be useful in the study of these spaces.
LA - eng
KW - Calkin algebra; essential spectrum; semi-Fredholm operator; hereditarily indecomposable Banach space
UR - http://eudml.org/doc/282332
ER -

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