Self-adjoint implies symmetry












0












$begingroup$


I have found little statement that I'd like to prove. It's about: self-adjoin operator implies that this operator is symmetric.
Definitions:
Operator T: H-> H (where H-Hilbert's) is symmetric, if = for every x,t in D(T). <-,-> is the scalar product.



Operator is self-adjoint if D(T)=D(T*) and $Tf=T$*$f$ for $f in D(T)$, where



$D(T*)= { y in H: |<Tx,y>| leq C_{y} ||x||, $ for every $ x in D(T)$.



Then proof of the following: If T is self-adjoint, then it's symmetric.



Let us take $x,t in D(T)$.



$<Tx,y> = <x, T$*$y>$, because T is self-adjoint.
And then:



$<x, T$*$y> = <x, Ty>$.



Can somebody explain why the last equation occurs? I can't explain it from which property it comes. And does the D(T) means domain in this example? Could this equation comes from equality D(T)=D(T*)?










share|cite|improve this question









$endgroup$












  • $begingroup$
    on LHS use the definition of $T^{*}$ and on RHS use the hypothesis that $T^{*}=T$.
    $endgroup$
    – Kavi Rama Murthy
    Jan 24 at 8:14


















0












$begingroup$


I have found little statement that I'd like to prove. It's about: self-adjoin operator implies that this operator is symmetric.
Definitions:
Operator T: H-> H (where H-Hilbert's) is symmetric, if = for every x,t in D(T). <-,-> is the scalar product.



Operator is self-adjoint if D(T)=D(T*) and $Tf=T$*$f$ for $f in D(T)$, where



$D(T*)= { y in H: |<Tx,y>| leq C_{y} ||x||, $ for every $ x in D(T)$.



Then proof of the following: If T is self-adjoint, then it's symmetric.



Let us take $x,t in D(T)$.



$<Tx,y> = <x, T$*$y>$, because T is self-adjoint.
And then:



$<x, T$*$y> = <x, Ty>$.



Can somebody explain why the last equation occurs? I can't explain it from which property it comes. And does the D(T) means domain in this example? Could this equation comes from equality D(T)=D(T*)?










share|cite|improve this question









$endgroup$












  • $begingroup$
    on LHS use the definition of $T^{*}$ and on RHS use the hypothesis that $T^{*}=T$.
    $endgroup$
    – Kavi Rama Murthy
    Jan 24 at 8:14
















0












0








0





$begingroup$


I have found little statement that I'd like to prove. It's about: self-adjoin operator implies that this operator is symmetric.
Definitions:
Operator T: H-> H (where H-Hilbert's) is symmetric, if = for every x,t in D(T). <-,-> is the scalar product.



Operator is self-adjoint if D(T)=D(T*) and $Tf=T$*$f$ for $f in D(T)$, where



$D(T*)= { y in H: |<Tx,y>| leq C_{y} ||x||, $ for every $ x in D(T)$.



Then proof of the following: If T is self-adjoint, then it's symmetric.



Let us take $x,t in D(T)$.



$<Tx,y> = <x, T$*$y>$, because T is self-adjoint.
And then:



$<x, T$*$y> = <x, Ty>$.



Can somebody explain why the last equation occurs? I can't explain it from which property it comes. And does the D(T) means domain in this example? Could this equation comes from equality D(T)=D(T*)?










share|cite|improve this question









$endgroup$




I have found little statement that I'd like to prove. It's about: self-adjoin operator implies that this operator is symmetric.
Definitions:
Operator T: H-> H (where H-Hilbert's) is symmetric, if = for every x,t in D(T). <-,-> is the scalar product.



Operator is self-adjoint if D(T)=D(T*) and $Tf=T$*$f$ for $f in D(T)$, where



$D(T*)= { y in H: |<Tx,y>| leq C_{y} ||x||, $ for every $ x in D(T)$.



Then proof of the following: If T is self-adjoint, then it's symmetric.



Let us take $x,t in D(T)$.



$<Tx,y> = <x, T$*$y>$, because T is self-adjoint.
And then:



$<x, T$*$y> = <x, Ty>$.



Can somebody explain why the last equation occurs? I can't explain it from which property it comes. And does the D(T) means domain in this example? Could this equation comes from equality D(T)=D(T*)?







self-adjoint-operators






share|cite|improve this question













share|cite|improve this question











share|cite|improve this question




share|cite|improve this question










asked Jan 24 at 8:07









OlgaOlga

176




176












  • $begingroup$
    on LHS use the definition of $T^{*}$ and on RHS use the hypothesis that $T^{*}=T$.
    $endgroup$
    – Kavi Rama Murthy
    Jan 24 at 8:14




















  • $begingroup$
    on LHS use the definition of $T^{*}$ and on RHS use the hypothesis that $T^{*}=T$.
    $endgroup$
    – Kavi Rama Murthy
    Jan 24 at 8:14


















$begingroup$
on LHS use the definition of $T^{*}$ and on RHS use the hypothesis that $T^{*}=T$.
$endgroup$
– Kavi Rama Murthy
Jan 24 at 8:14






$begingroup$
on LHS use the definition of $T^{*}$ and on RHS use the hypothesis that $T^{*}=T$.
$endgroup$
– Kavi Rama Murthy
Jan 24 at 8:14












0






active

oldest

votes











Your Answer





StackExchange.ifUsing("editor", function () {
return StackExchange.using("mathjaxEditing", function () {
StackExchange.MarkdownEditor.creationCallbacks.add(function (editor, postfix) {
StackExchange.mathjaxEditing.prepareWmdForMathJax(editor, postfix, [["$", "$"], ["\\(","\\)"]]);
});
});
}, "mathjax-editing");

StackExchange.ready(function() {
var channelOptions = {
tags: "".split(" "),
id: "69"
};
initTagRenderer("".split(" "), "".split(" "), channelOptions);

StackExchange.using("externalEditor", function() {
// Have to fire editor after snippets, if snippets enabled
if (StackExchange.settings.snippets.snippetsEnabled) {
StackExchange.using("snippets", function() {
createEditor();
});
}
else {
createEditor();
}
});

function createEditor() {
StackExchange.prepareEditor({
heartbeatType: 'answer',
autoActivateHeartbeat: false,
convertImagesToLinks: true,
noModals: true,
showLowRepImageUploadWarning: true,
reputationToPostImages: 10,
bindNavPrevention: true,
postfix: "",
imageUploader: {
brandingHtml: "Powered by u003ca class="icon-imgur-white" href="https://imgur.com/"u003eu003c/au003e",
contentPolicyHtml: "User contributions licensed under u003ca href="https://creativecommons.org/licenses/by-sa/3.0/"u003ecc by-sa 3.0 with attribution requiredu003c/au003e u003ca href="https://stackoverflow.com/legal/content-policy"u003e(content policy)u003c/au003e",
allowUrls: true
},
noCode: true, onDemand: true,
discardSelector: ".discard-answer"
,immediatelyShowMarkdownHelp:true
});


}
});














draft saved

draft discarded


















StackExchange.ready(
function () {
StackExchange.openid.initPostLogin('.new-post-login', 'https%3a%2f%2fmath.stackexchange.com%2fquestions%2f3085599%2fself-adjoint-implies-symmetry%23new-answer', 'question_page');
}
);

Post as a guest















Required, but never shown

























0






active

oldest

votes








0






active

oldest

votes









active

oldest

votes






active

oldest

votes
















draft saved

draft discarded




















































Thanks for contributing an answer to Mathematics Stack Exchange!


  • Please be sure to answer the question. Provide details and share your research!

But avoid



  • Asking for help, clarification, or responding to other answers.

  • Making statements based on opinion; back them up with references or personal experience.


Use MathJax to format equations. MathJax reference.


To learn more, see our tips on writing great answers.




draft saved


draft discarded














StackExchange.ready(
function () {
StackExchange.openid.initPostLogin('.new-post-login', 'https%3a%2f%2fmath.stackexchange.com%2fquestions%2f3085599%2fself-adjoint-implies-symmetry%23new-answer', 'question_page');
}
);

Post as a guest















Required, but never shown





















































Required, but never shown














Required, but never shown












Required, but never shown







Required, but never shown

































Required, but never shown














Required, but never shown












Required, but never shown







Required, but never shown







Popular posts from this blog

MongoDB - Not Authorized To Execute Command

in spring boot 2.1 many test slices are not allowed anymore due to multiple @BootstrapWith

How to fix TextFormField cause rebuild widget in Flutter