## Linear Operators: Spectral theory |

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Page 907

negative real axis respectively . Proof . If N is a bounded normal operator then ,

by Corollary IX . 3 . 15 , NN * = N * N = I if and only if zā = 1 for every spectral ...

**positive**if and only if its spectrum lies on the unit circle , the real axis , or the non -negative real axis respectively . Proof . If N is a bounded normal operator then ,

by Corollary IX . 3 . 15 , NN * = N * N = I if and only if zā = 1 for every spectral ...

Page 1247

Q . E . D . Next we shall require some information on

transformations and their square roots . 2 LEMMA . A self adjoint transformation T

is

be the ...

Q . E . D . Next we shall require some information on

**positive**self adjointtransformations and their square roots . 2 LEMMA . A self adjoint transformation T

is

**positive**if and only if o ( T ) is a subset of the interval [ 0 , 00 ) . PROOF . Let Ebe the ...

Page 1338

Let { uis } be a

respect to a

defined by the equations Mijle ) = 5 . m . ; ( 2 ) u ( da ) , where e is any bounded

Borel ...

Let { uis } be a

**positive**matrix measure whose elements Mis are continuous withrespect to a

**positive**o - finite measure u . If the matrix of densities { mi ; } isdefined by the equations Mijle ) = 5 . m . ; ( 2 ) u ( da ) , where e is any bounded

Borel ...

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### Contents

IX | 859 |

Bounded Normal Operators in Hilbert Space | 887 |

Compact Groups | 945 |

Copyright | |

46 other sections not shown

### Other editions - View all

Linear Operators, Part 1 Nelson Dunford,Jacob T. Schwartz,William G. Bade,Robert G. Bartle Snippet view - 1958 |

### Common terms and phrases

additive adjoint operator algebra Amer analytic assume Banach spaces basis belongs Borel boundary conditions boundary values bounded called clear closed closure coefficients compact complex Consequently consider constant contains continuous converges Corollary corresponding defined Definition denote dense derivatives determined domain eigenvalues element equal equation essential spectrum evident Exercise exists extension finite follows formal differential operator formula function given Hence Hilbert space identity independent indices inequality integral interval Lemma limit linear mapping Math matrix measure multiplicity neighborhood norm obtained partial positive preceding present problem projection proof properties prove range regular remark representation respectively restriction result satisfies seen sequence shown singular solution spectral square-integrable statement subset subspace sufficiently Suppose symmetric Theorem theory topology transform unique vanishes vector zero