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Banach Algebras Spectrum and Holomorphic Functional Calculus

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1 · Prerequisites
Abstract Algebra
Combinatorics
Complex Analysis
Functional Analysis
Linear Algebra
Measure Theory
Real Analysis
Set Theory
Topology
2 · Logical flowchart

3 · Items

Definition

Unital Banach algebra

Definition

Invertible element and general linear group of a Banach algebra

Lemma

Neumann series

Theorem

Invertible group is open and inversion is continuous

Definition

Spectrum and resolvent set in a Banach algebra

Lemma

Resolvent identity

Theorem

Resolvent is Banach-valued holomorphic

Theorem

Spectrum is nonempty compact and norm bounded

Definition

Spectral radius

Theorem

Polynomial spectral mapping

Lemma

Submultiplicative root limit

Theorem

Spectral radius formula

Lemma

Canonical Banach complexification of a real Banach space

Definition

Complexification and spectrum of a real operator

Theorem

Gelfand-Mazur

Definition

Banach algebra valued contour integral

Lemma

Contour integral commutes with bounded linear maps

Lemma

Banach-valued Cauchy integral vanishes

Lemma

Admissible cycle around a compact plane set

Definition

Holomorphic functional calculus

Lemma

Holomorphic functional calculus is contour independent

Theorem

Holomorphic functional calculus homomorphism

Theorem

Holomorphic spectral mapping and composition

Definition

Riesz spectral projection

Theorem

Riesz spectral projection properties

Definition

Calkin algebra

Corollary

Atkinson in Calkin algebra language

Definition

Point continuous and residual spectrum

Definition

Approximate point and compression spectrum

Lemma

Relations among the five spectral parts

Theorem

Boundary of spectrum lies in approximate point spectrum

Sources