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Page 488
If the adjoint of an operator U in B ( X , Y ) is one - to - one and has a closed range , then UX = Y. PROOF . Let 0 #ye Y and define I = { y * y * € Y * , y * y = 0 } . Then I ' is Y - closed in Y * . Suppose , for the moment , that U ...
If the adjoint of an operator U in B ( X , Y ) is one - to - one and has a closed range , then UX = Y. PROOF . Let 0 #ye Y and define I = { y * y * € Y * , y * y = 0 } . Then I ' is Y - closed in Y * . Suppose , for the moment , that U ...
Page 489
since the range of U * is closed , æ * U * y * for some y * e Y * . If z * is the restriction of y * to 3 , then x * = U ** . Hence , the range of U * is also closed . It follows from the previous lemma that U_X = UX 3 .
since the range of U * is closed , æ * U * y * for some y * e Y * . If z * is the restriction of y * to 3 , then x * = U ** . Hence , the range of U * is also closed . It follows from the previous lemma that U_X = UX 3 .
Page 513
( ii ) The range of U is closed if there exists a constant K such that for any y in the range there exists a solution of y Tæ such that x Skyl . ( iii ) U is one - to - one if the range of U * is dense in X * .
( ii ) The range of U is closed if there exists a constant K such that for any y in the range there exists a solution of y Tæ such that x Skyl . ( iii ) U is one - to - one if the range of U * is dense in X * .
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Contents
Preliminary Concepts | 1 |
The VitaliHahnSaks Theorem and Spaces of Measures | 7 |
B Topological Preliminaries | 10 |
Copyright | |
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Akad algebra Amer analytic applied arbitrary assumed B-space Banach Banach spaces bounded called clear closed closure complex condition Consequently contains continuous functions converges Corollary defined DEFINITION denote dense determined differential disjoint element equation equivalent everywhere Exercise exists extension field finite follows formula function f given Hence Hilbert space implies integral interval isomorphism Lebesgue Lemma limit linear functional linear operator linear space linear topological space Math means measure space metric space neighborhood norm open set operator problem Proc projection Proof properties proved range reflexive respect Russian satisfies scalar seen semi-group separable sequence set function Show shown statement subset subspace sufficient Suppose Theorem theory topology u-measurable uniform uniformly unique unit sphere valued vector weak weakly compact zero