Minimize trace of $A$ given that $A−N$ is positive semi-definite and $A$ is diagonal











up vote
1
down vote

favorite












begin{array}{ll} text{minimize} & mbox{tr} (mathrm A)\ text{subject to} & mathrm A - mathrm N succeq mathrm O_nend{array} where $A$ and $N$ are pd matrices, and $A$ is diagonal.



There is a related post: Minimize trace of $A$ given that $A-N$ is positive semi-definite. . However, in that case $A$ is not diagonal thus, $tr(A)=tr(N)$ is possible, while in current case not.



For $Ain mathbb{R}^{2times2}$, I believe $min tr(A)=sum n_{ij}$, however for $Ain mathbb{R}^{3times3}$ we have inequality $min tr(A)leqsum n_{ij}$. Can you please help with analytical approach so solve it










share|cite|improve this question






















  • $A =lambda_{max}(N)I$ is feasible, so $n lambda_{max}(N)$ is an obvious bound. I do not see an easy way to get a tighter bound.
    – LinAlg
    Nov 19 at 14:14










  • If $N=begin{bmatrix}3 & 1 & -1\1 & 2 &1 \-1 & 1 &2end{bmatrix}>0$, then $nlambda_{max}(N)=11.1963$. Let $A=begin{bmatrix}4 & & \ & 3 & \ & &3end{bmatrix}$, then $A-Ngeq 0$ and $trace(A)=10$
    – Lee
    Nov 20 at 1:57












  • if $A=begin{bmatrix}4 & & \ & 3 & \ & &2end{bmatrix}$, then again $A-Ngeq 0$ and $trace(A)=9$. I think this is minimum, but I don't have a proof
    – Lee
    Nov 20 at 2:19










  • if $N$ is one of following structures $begin{bmatrix}+& + & +\+ & + &+ \+ & + &+end{bmatrix}$, $begin{bmatrix}+& - & +\- & + &- \+ & - &+end{bmatrix}$, $begin{bmatrix}+& - &-\- & + &+ \- & + &+end{bmatrix}$, $begin{bmatrix}+& + & -\+ & + &- \- & - &+end{bmatrix}$, then I believe $min tr(A)=sum n_{ij}$.
    – Lee
    Nov 20 at 2:26










  • if $N$ is one of following structures $begin{bmatrix}+& + & -\+ & + &+ \- & + &+end{bmatrix}$, $begin{bmatrix}+& - & +\- & + &+ \+ & + &+end{bmatrix}$, $begin{bmatrix}+& + &+\+ & + &- \+ & - &+end{bmatrix}$, then I believe $min tr(A)=sum |n_{ij}|-4|n_{12}| $, assuming $|n_{12}|leq |n_{13}| leq |n_{23}|$.
    – Lee
    Nov 20 at 9:12

















up vote
1
down vote

favorite












begin{array}{ll} text{minimize} & mbox{tr} (mathrm A)\ text{subject to} & mathrm A - mathrm N succeq mathrm O_nend{array} where $A$ and $N$ are pd matrices, and $A$ is diagonal.



There is a related post: Minimize trace of $A$ given that $A-N$ is positive semi-definite. . However, in that case $A$ is not diagonal thus, $tr(A)=tr(N)$ is possible, while in current case not.



For $Ain mathbb{R}^{2times2}$, I believe $min tr(A)=sum n_{ij}$, however for $Ain mathbb{R}^{3times3}$ we have inequality $min tr(A)leqsum n_{ij}$. Can you please help with analytical approach so solve it










share|cite|improve this question






















  • $A =lambda_{max}(N)I$ is feasible, so $n lambda_{max}(N)$ is an obvious bound. I do not see an easy way to get a tighter bound.
    – LinAlg
    Nov 19 at 14:14










  • If $N=begin{bmatrix}3 & 1 & -1\1 & 2 &1 \-1 & 1 &2end{bmatrix}>0$, then $nlambda_{max}(N)=11.1963$. Let $A=begin{bmatrix}4 & & \ & 3 & \ & &3end{bmatrix}$, then $A-Ngeq 0$ and $trace(A)=10$
    – Lee
    Nov 20 at 1:57












  • if $A=begin{bmatrix}4 & & \ & 3 & \ & &2end{bmatrix}$, then again $A-Ngeq 0$ and $trace(A)=9$. I think this is minimum, but I don't have a proof
    – Lee
    Nov 20 at 2:19










  • if $N$ is one of following structures $begin{bmatrix}+& + & +\+ & + &+ \+ & + &+end{bmatrix}$, $begin{bmatrix}+& - & +\- & + &- \+ & - &+end{bmatrix}$, $begin{bmatrix}+& - &-\- & + &+ \- & + &+end{bmatrix}$, $begin{bmatrix}+& + & -\+ & + &- \- & - &+end{bmatrix}$, then I believe $min tr(A)=sum n_{ij}$.
    – Lee
    Nov 20 at 2:26










  • if $N$ is one of following structures $begin{bmatrix}+& + & -\+ & + &+ \- & + &+end{bmatrix}$, $begin{bmatrix}+& - & +\- & + &+ \+ & + &+end{bmatrix}$, $begin{bmatrix}+& + &+\+ & + &- \+ & - &+end{bmatrix}$, then I believe $min tr(A)=sum |n_{ij}|-4|n_{12}| $, assuming $|n_{12}|leq |n_{13}| leq |n_{23}|$.
    – Lee
    Nov 20 at 9:12















up vote
1
down vote

favorite









up vote
1
down vote

favorite











begin{array}{ll} text{minimize} & mbox{tr} (mathrm A)\ text{subject to} & mathrm A - mathrm N succeq mathrm O_nend{array} where $A$ and $N$ are pd matrices, and $A$ is diagonal.



There is a related post: Minimize trace of $A$ given that $A-N$ is positive semi-definite. . However, in that case $A$ is not diagonal thus, $tr(A)=tr(N)$ is possible, while in current case not.



For $Ain mathbb{R}^{2times2}$, I believe $min tr(A)=sum n_{ij}$, however for $Ain mathbb{R}^{3times3}$ we have inequality $min tr(A)leqsum n_{ij}$. Can you please help with analytical approach so solve it










share|cite|improve this question













begin{array}{ll} text{minimize} & mbox{tr} (mathrm A)\ text{subject to} & mathrm A - mathrm N succeq mathrm O_nend{array} where $A$ and $N$ are pd matrices, and $A$ is diagonal.



There is a related post: Minimize trace of $A$ given that $A-N$ is positive semi-definite. . However, in that case $A$ is not diagonal thus, $tr(A)=tr(N)$ is possible, while in current case not.



For $Ain mathbb{R}^{2times2}$, I believe $min tr(A)=sum n_{ij}$, however for $Ain mathbb{R}^{3times3}$ we have inequality $min tr(A)leqsum n_{ij}$. Can you please help with analytical approach so solve it







optimization maxima-minima trace






share|cite|improve this question













share|cite|improve this question











share|cite|improve this question




share|cite|improve this question










asked Nov 19 at 3:24









Lee

907




907












  • $A =lambda_{max}(N)I$ is feasible, so $n lambda_{max}(N)$ is an obvious bound. I do not see an easy way to get a tighter bound.
    – LinAlg
    Nov 19 at 14:14










  • If $N=begin{bmatrix}3 & 1 & -1\1 & 2 &1 \-1 & 1 &2end{bmatrix}>0$, then $nlambda_{max}(N)=11.1963$. Let $A=begin{bmatrix}4 & & \ & 3 & \ & &3end{bmatrix}$, then $A-Ngeq 0$ and $trace(A)=10$
    – Lee
    Nov 20 at 1:57












  • if $A=begin{bmatrix}4 & & \ & 3 & \ & &2end{bmatrix}$, then again $A-Ngeq 0$ and $trace(A)=9$. I think this is minimum, but I don't have a proof
    – Lee
    Nov 20 at 2:19










  • if $N$ is one of following structures $begin{bmatrix}+& + & +\+ & + &+ \+ & + &+end{bmatrix}$, $begin{bmatrix}+& - & +\- & + &- \+ & - &+end{bmatrix}$, $begin{bmatrix}+& - &-\- & + &+ \- & + &+end{bmatrix}$, $begin{bmatrix}+& + & -\+ & + &- \- & - &+end{bmatrix}$, then I believe $min tr(A)=sum n_{ij}$.
    – Lee
    Nov 20 at 2:26










  • if $N$ is one of following structures $begin{bmatrix}+& + & -\+ & + &+ \- & + &+end{bmatrix}$, $begin{bmatrix}+& - & +\- & + &+ \+ & + &+end{bmatrix}$, $begin{bmatrix}+& + &+\+ & + &- \+ & - &+end{bmatrix}$, then I believe $min tr(A)=sum |n_{ij}|-4|n_{12}| $, assuming $|n_{12}|leq |n_{13}| leq |n_{23}|$.
    – Lee
    Nov 20 at 9:12




















  • $A =lambda_{max}(N)I$ is feasible, so $n lambda_{max}(N)$ is an obvious bound. I do not see an easy way to get a tighter bound.
    – LinAlg
    Nov 19 at 14:14










  • If $N=begin{bmatrix}3 & 1 & -1\1 & 2 &1 \-1 & 1 &2end{bmatrix}>0$, then $nlambda_{max}(N)=11.1963$. Let $A=begin{bmatrix}4 & & \ & 3 & \ & &3end{bmatrix}$, then $A-Ngeq 0$ and $trace(A)=10$
    – Lee
    Nov 20 at 1:57












  • if $A=begin{bmatrix}4 & & \ & 3 & \ & &2end{bmatrix}$, then again $A-Ngeq 0$ and $trace(A)=9$. I think this is minimum, but I don't have a proof
    – Lee
    Nov 20 at 2:19










  • if $N$ is one of following structures $begin{bmatrix}+& + & +\+ & + &+ \+ & + &+end{bmatrix}$, $begin{bmatrix}+& - & +\- & + &- \+ & - &+end{bmatrix}$, $begin{bmatrix}+& - &-\- & + &+ \- & + &+end{bmatrix}$, $begin{bmatrix}+& + & -\+ & + &- \- & - &+end{bmatrix}$, then I believe $min tr(A)=sum n_{ij}$.
    – Lee
    Nov 20 at 2:26










  • if $N$ is one of following structures $begin{bmatrix}+& + & -\+ & + &+ \- & + &+end{bmatrix}$, $begin{bmatrix}+& - & +\- & + &+ \+ & + &+end{bmatrix}$, $begin{bmatrix}+& + &+\+ & + &- \+ & - &+end{bmatrix}$, then I believe $min tr(A)=sum |n_{ij}|-4|n_{12}| $, assuming $|n_{12}|leq |n_{13}| leq |n_{23}|$.
    – Lee
    Nov 20 at 9:12


















$A =lambda_{max}(N)I$ is feasible, so $n lambda_{max}(N)$ is an obvious bound. I do not see an easy way to get a tighter bound.
– LinAlg
Nov 19 at 14:14




$A =lambda_{max}(N)I$ is feasible, so $n lambda_{max}(N)$ is an obvious bound. I do not see an easy way to get a tighter bound.
– LinAlg
Nov 19 at 14:14












If $N=begin{bmatrix}3 & 1 & -1\1 & 2 &1 \-1 & 1 &2end{bmatrix}>0$, then $nlambda_{max}(N)=11.1963$. Let $A=begin{bmatrix}4 & & \ & 3 & \ & &3end{bmatrix}$, then $A-Ngeq 0$ and $trace(A)=10$
– Lee
Nov 20 at 1:57






If $N=begin{bmatrix}3 & 1 & -1\1 & 2 &1 \-1 & 1 &2end{bmatrix}>0$, then $nlambda_{max}(N)=11.1963$. Let $A=begin{bmatrix}4 & & \ & 3 & \ & &3end{bmatrix}$, then $A-Ngeq 0$ and $trace(A)=10$
– Lee
Nov 20 at 1:57














if $A=begin{bmatrix}4 & & \ & 3 & \ & &2end{bmatrix}$, then again $A-Ngeq 0$ and $trace(A)=9$. I think this is minimum, but I don't have a proof
– Lee
Nov 20 at 2:19




if $A=begin{bmatrix}4 & & \ & 3 & \ & &2end{bmatrix}$, then again $A-Ngeq 0$ and $trace(A)=9$. I think this is minimum, but I don't have a proof
– Lee
Nov 20 at 2:19












if $N$ is one of following structures $begin{bmatrix}+& + & +\+ & + &+ \+ & + &+end{bmatrix}$, $begin{bmatrix}+& - & +\- & + &- \+ & - &+end{bmatrix}$, $begin{bmatrix}+& - &-\- & + &+ \- & + &+end{bmatrix}$, $begin{bmatrix}+& + & -\+ & + &- \- & - &+end{bmatrix}$, then I believe $min tr(A)=sum n_{ij}$.
– Lee
Nov 20 at 2:26




if $N$ is one of following structures $begin{bmatrix}+& + & +\+ & + &+ \+ & + &+end{bmatrix}$, $begin{bmatrix}+& - & +\- & + &- \+ & - &+end{bmatrix}$, $begin{bmatrix}+& - &-\- & + &+ \- & + &+end{bmatrix}$, $begin{bmatrix}+& + & -\+ & + &- \- & - &+end{bmatrix}$, then I believe $min tr(A)=sum n_{ij}$.
– Lee
Nov 20 at 2:26












if $N$ is one of following structures $begin{bmatrix}+& + & -\+ & + &+ \- & + &+end{bmatrix}$, $begin{bmatrix}+& - & +\- & + &+ \+ & + &+end{bmatrix}$, $begin{bmatrix}+& + &+\+ & + &- \+ & - &+end{bmatrix}$, then I believe $min tr(A)=sum |n_{ij}|-4|n_{12}| $, assuming $|n_{12}|leq |n_{13}| leq |n_{23}|$.
– Lee
Nov 20 at 9:12






if $N$ is one of following structures $begin{bmatrix}+& + & -\+ & + &+ \- & + &+end{bmatrix}$, $begin{bmatrix}+& - & +\- & + &+ \+ & + &+end{bmatrix}$, $begin{bmatrix}+& + &+\+ & + &- \+ & - &+end{bmatrix}$, then I believe $min tr(A)=sum |n_{ij}|-4|n_{12}| $, assuming $|n_{12}|leq |n_{13}| leq |n_{23}|$.
– Lee
Nov 20 at 9:12

















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',
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%2f3004480%2fminimize-trace-of-a-given-that-a%25e2%2588%2592n-is-positive-semi-definite-and-a-is-diag%23new-answer', 'question_page');
}
);

Post as a guest















Required, but never shown






























active

oldest

votes













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.





Some of your past answers have not been well-received, and you're in danger of being blocked from answering.


Please pay close attention to the following guidance:


  • 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.


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%2f3004480%2fminimize-trace-of-a-given-that-a%25e2%2588%2592n-is-positive-semi-definite-and-a-is-diag%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

How to change which sound is reproduced for terminal bell?

Can I use Tabulator js library in my java Spring + Thymeleaf project?

Title Spacing in Bjornstrup Chapter, Removing Chapter Number From Contents