Prove $|tr(PAP') - tr(PBP')| leq ||A-B||_{infty} ||P'||_1^2$
$begingroup$
How can I show the following identity?
$|text{tr}(PAP') - text{tr}(PBP')| leq ||A-B||_{infty} ||P'||_1^2$
linear-algebra norm
$endgroup$
add a comment |
$begingroup$
How can I show the following identity?
$|text{tr}(PAP') - text{tr}(PBP')| leq ||A-B||_{infty} ||P'||_1^2$
linear-algebra norm
$endgroup$
3
$begingroup$
What is $P$ (and what happened to him)?
$endgroup$
– lcv
Jan 25 at 1:07
$begingroup$
@lcv: $P$ is a matrix that I am interested in estimating. I am not sure what you are trying to mean by "what happened to him"?
$endgroup$
– shani
Jan 25 at 1:20
$begingroup$
What is the relationship between $P$ and $P'$?
$endgroup$
– Kenny Wong
Jan 25 at 8:16
$begingroup$
$P'$ is the transpose of $P$.
$endgroup$
– shani
Jan 25 at 8:18
add a comment |
$begingroup$
How can I show the following identity?
$|text{tr}(PAP') - text{tr}(PBP')| leq ||A-B||_{infty} ||P'||_1^2$
linear-algebra norm
$endgroup$
How can I show the following identity?
$|text{tr}(PAP') - text{tr}(PBP')| leq ||A-B||_{infty} ||P'||_1^2$
linear-algebra norm
linear-algebra norm
asked Jan 25 at 0:37
shanishani
1458
1458
3
$begingroup$
What is $P$ (and what happened to him)?
$endgroup$
– lcv
Jan 25 at 1:07
$begingroup$
@lcv: $P$ is a matrix that I am interested in estimating. I am not sure what you are trying to mean by "what happened to him"?
$endgroup$
– shani
Jan 25 at 1:20
$begingroup$
What is the relationship between $P$ and $P'$?
$endgroup$
– Kenny Wong
Jan 25 at 8:16
$begingroup$
$P'$ is the transpose of $P$.
$endgroup$
– shani
Jan 25 at 8:18
add a comment |
3
$begingroup$
What is $P$ (and what happened to him)?
$endgroup$
– lcv
Jan 25 at 1:07
$begingroup$
@lcv: $P$ is a matrix that I am interested in estimating. I am not sure what you are trying to mean by "what happened to him"?
$endgroup$
– shani
Jan 25 at 1:20
$begingroup$
What is the relationship between $P$ and $P'$?
$endgroup$
– Kenny Wong
Jan 25 at 8:16
$begingroup$
$P'$ is the transpose of $P$.
$endgroup$
– shani
Jan 25 at 8:18
3
3
$begingroup$
What is $P$ (and what happened to him)?
$endgroup$
– lcv
Jan 25 at 1:07
$begingroup$
What is $P$ (and what happened to him)?
$endgroup$
– lcv
Jan 25 at 1:07
$begingroup$
@lcv: $P$ is a matrix that I am interested in estimating. I am not sure what you are trying to mean by "what happened to him"?
$endgroup$
– shani
Jan 25 at 1:20
$begingroup$
@lcv: $P$ is a matrix that I am interested in estimating. I am not sure what you are trying to mean by "what happened to him"?
$endgroup$
– shani
Jan 25 at 1:20
$begingroup$
What is the relationship between $P$ and $P'$?
$endgroup$
– Kenny Wong
Jan 25 at 8:16
$begingroup$
What is the relationship between $P$ and $P'$?
$endgroup$
– Kenny Wong
Jan 25 at 8:16
$begingroup$
$P'$ is the transpose of $P$.
$endgroup$
– shani
Jan 25 at 8:18
$begingroup$
$P'$ is the transpose of $P$.
$endgroup$
– shani
Jan 25 at 8:18
add a comment |
1 Answer
1
active
oldest
votes
$begingroup$
You have
$$
|text{tr}(PAP') - text{tr}(PBP')|=|text{tr}(PAP'-PBP')|=|text{tr}(P(A-B)P')|=|text{tr}((A-B)P'P)|.
$$
Now you apply the well-known Hölder inequality
$$
|text{tr}(XY)|leq |X|_infty,|Y|_1.
$$
If you don't see it, here are more details. From the above, you get
$$
|text{tr}(PAP') - text{tr}(PBP')|leq|A-B|_infty,|P'P|_1.
$$
With ${mu_j}$ the singular values of $P$, you have $$|P'P|_1=sum_jmu_j^2leqleft(sum_jmu_jright)^2=|P|_1^2.$$
$endgroup$
$begingroup$
Is there a type in the Holder's inequality? What happened to Y? I can't see how this can be used to prove the upper bound
$endgroup$
– shani
Jan 25 at 2:05
$begingroup$
Yes, the second one was a $Y$.
$endgroup$
– Martin Argerami
Jan 25 at 2:05
add a comment |
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
});
}
});
Sign up or log in
StackExchange.ready(function () {
StackExchange.helpers.onClickDraftSave('#login-link');
});
Sign up using Google
Sign up using Facebook
Sign up using Email and Password
Post as a guest
Required, but never shown
StackExchange.ready(
function () {
StackExchange.openid.initPostLogin('.new-post-login', 'https%3a%2f%2fmath.stackexchange.com%2fquestions%2f3086564%2fprove-trpap-trpbp-leq-a-b-infty-p-12%23new-answer', 'question_page');
}
);
Post as a guest
Required, but never shown
1 Answer
1
active
oldest
votes
1 Answer
1
active
oldest
votes
active
oldest
votes
active
oldest
votes
$begingroup$
You have
$$
|text{tr}(PAP') - text{tr}(PBP')|=|text{tr}(PAP'-PBP')|=|text{tr}(P(A-B)P')|=|text{tr}((A-B)P'P)|.
$$
Now you apply the well-known Hölder inequality
$$
|text{tr}(XY)|leq |X|_infty,|Y|_1.
$$
If you don't see it, here are more details. From the above, you get
$$
|text{tr}(PAP') - text{tr}(PBP')|leq|A-B|_infty,|P'P|_1.
$$
With ${mu_j}$ the singular values of $P$, you have $$|P'P|_1=sum_jmu_j^2leqleft(sum_jmu_jright)^2=|P|_1^2.$$
$endgroup$
$begingroup$
Is there a type in the Holder's inequality? What happened to Y? I can't see how this can be used to prove the upper bound
$endgroup$
– shani
Jan 25 at 2:05
$begingroup$
Yes, the second one was a $Y$.
$endgroup$
– Martin Argerami
Jan 25 at 2:05
add a comment |
$begingroup$
You have
$$
|text{tr}(PAP') - text{tr}(PBP')|=|text{tr}(PAP'-PBP')|=|text{tr}(P(A-B)P')|=|text{tr}((A-B)P'P)|.
$$
Now you apply the well-known Hölder inequality
$$
|text{tr}(XY)|leq |X|_infty,|Y|_1.
$$
If you don't see it, here are more details. From the above, you get
$$
|text{tr}(PAP') - text{tr}(PBP')|leq|A-B|_infty,|P'P|_1.
$$
With ${mu_j}$ the singular values of $P$, you have $$|P'P|_1=sum_jmu_j^2leqleft(sum_jmu_jright)^2=|P|_1^2.$$
$endgroup$
$begingroup$
Is there a type in the Holder's inequality? What happened to Y? I can't see how this can be used to prove the upper bound
$endgroup$
– shani
Jan 25 at 2:05
$begingroup$
Yes, the second one was a $Y$.
$endgroup$
– Martin Argerami
Jan 25 at 2:05
add a comment |
$begingroup$
You have
$$
|text{tr}(PAP') - text{tr}(PBP')|=|text{tr}(PAP'-PBP')|=|text{tr}(P(A-B)P')|=|text{tr}((A-B)P'P)|.
$$
Now you apply the well-known Hölder inequality
$$
|text{tr}(XY)|leq |X|_infty,|Y|_1.
$$
If you don't see it, here are more details. From the above, you get
$$
|text{tr}(PAP') - text{tr}(PBP')|leq|A-B|_infty,|P'P|_1.
$$
With ${mu_j}$ the singular values of $P$, you have $$|P'P|_1=sum_jmu_j^2leqleft(sum_jmu_jright)^2=|P|_1^2.$$
$endgroup$
You have
$$
|text{tr}(PAP') - text{tr}(PBP')|=|text{tr}(PAP'-PBP')|=|text{tr}(P(A-B)P')|=|text{tr}((A-B)P'P)|.
$$
Now you apply the well-known Hölder inequality
$$
|text{tr}(XY)|leq |X|_infty,|Y|_1.
$$
If you don't see it, here are more details. From the above, you get
$$
|text{tr}(PAP') - text{tr}(PBP')|leq|A-B|_infty,|P'P|_1.
$$
With ${mu_j}$ the singular values of $P$, you have $$|P'P|_1=sum_jmu_j^2leqleft(sum_jmu_jright)^2=|P|_1^2.$$
edited Jan 25 at 3:52
answered Jan 25 at 1:36


Martin ArgeramiMartin Argerami
128k1184184
128k1184184
$begingroup$
Is there a type in the Holder's inequality? What happened to Y? I can't see how this can be used to prove the upper bound
$endgroup$
– shani
Jan 25 at 2:05
$begingroup$
Yes, the second one was a $Y$.
$endgroup$
– Martin Argerami
Jan 25 at 2:05
add a comment |
$begingroup$
Is there a type in the Holder's inequality? What happened to Y? I can't see how this can be used to prove the upper bound
$endgroup$
– shani
Jan 25 at 2:05
$begingroup$
Yes, the second one was a $Y$.
$endgroup$
– Martin Argerami
Jan 25 at 2:05
$begingroup$
Is there a type in the Holder's inequality? What happened to Y? I can't see how this can be used to prove the upper bound
$endgroup$
– shani
Jan 25 at 2:05
$begingroup$
Is there a type in the Holder's inequality? What happened to Y? I can't see how this can be used to prove the upper bound
$endgroup$
– shani
Jan 25 at 2:05
$begingroup$
Yes, the second one was a $Y$.
$endgroup$
– Martin Argerami
Jan 25 at 2:05
$begingroup$
Yes, the second one was a $Y$.
$endgroup$
– Martin Argerami
Jan 25 at 2:05
add a comment |
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.
Sign up or log in
StackExchange.ready(function () {
StackExchange.helpers.onClickDraftSave('#login-link');
});
Sign up using Google
Sign up using Facebook
Sign up using Email and Password
Post as a guest
Required, but never shown
StackExchange.ready(
function () {
StackExchange.openid.initPostLogin('.new-post-login', 'https%3a%2f%2fmath.stackexchange.com%2fquestions%2f3086564%2fprove-trpap-trpbp-leq-a-b-infty-p-12%23new-answer', 'question_page');
}
);
Post as a guest
Required, but never shown
Sign up or log in
StackExchange.ready(function () {
StackExchange.helpers.onClickDraftSave('#login-link');
});
Sign up using Google
Sign up using Facebook
Sign up using Email and Password
Post as a guest
Required, but never shown
Sign up or log in
StackExchange.ready(function () {
StackExchange.helpers.onClickDraftSave('#login-link');
});
Sign up using Google
Sign up using Facebook
Sign up using Email and Password
Post as a guest
Required, but never shown
Sign up or log in
StackExchange.ready(function () {
StackExchange.helpers.onClickDraftSave('#login-link');
});
Sign up using Google
Sign up using Facebook
Sign up using Email and Password
Sign up using Google
Sign up using Facebook
Sign up using Email and Password
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
3
$begingroup$
What is $P$ (and what happened to him)?
$endgroup$
– lcv
Jan 25 at 1:07
$begingroup$
@lcv: $P$ is a matrix that I am interested in estimating. I am not sure what you are trying to mean by "what happened to him"?
$endgroup$
– shani
Jan 25 at 1:20
$begingroup$
What is the relationship between $P$ and $P'$?
$endgroup$
– Kenny Wong
Jan 25 at 8:16
$begingroup$
$P'$ is the transpose of $P$.
$endgroup$
– shani
Jan 25 at 8:18