What does Arg {Inf I(d)} means?












0












$begingroup$


I am currently studying the phase-field method for fracture modeling. In an article by Miehe -"Thermodynamically consistent phase-field models of fracture: Variational principles and multi-field FE implementation", I came across on an identity that I don't understand basically it says:
$$
d = mbox{Arg}left{inf_{d in W} I(d)right}.
$$

This expression came from the Euler type differential equation
$$
d(x) - l^2d''(x) = 0,
$$

which has the solution as an exponential function
$$
d(x) = exp(-|x|/l)
$$

Variational principle of this differential equation is ,
$$
d = mbox{Arg}left{inf_{d in W} I(d)right}.
$$

with $$ W = {d | d(0)=1, d(pm infty)=0}$$
where I(d) is a functional defined as an integral
$$
I(d) = frac{1}{2}int [d^2 + l^2d'^2] dV,
$$

and $l$ is a parameter.



Can anyone tell me what does that mean?










share|cite|improve this question











$endgroup$












  • $begingroup$
    Can you provide more context please? What is $I$? Maybe a function?
    $endgroup$
    – Dog_69
    Jan 17 at 9:42






  • 2




    $begingroup$
    Welcome to MSE. It is in your best interest that you type your questions (using MathJax) instead of posting links to pictures.
    $endgroup$
    – José Carlos Santos
    Jan 17 at 9:43










  • $begingroup$
    A pdf of the mentioned article is available here.
    $endgroup$
    – Mees de Vries
    Jan 17 at 9:47










  • $begingroup$
    It appears to simply be saying: find the infimum of the set $I(d)$ and return the argument, $d$, for the $I(d)$ that is the infimum.
    $endgroup$
    – Andy Walls
    Jan 17 at 13:20


















0












$begingroup$


I am currently studying the phase-field method for fracture modeling. In an article by Miehe -"Thermodynamically consistent phase-field models of fracture: Variational principles and multi-field FE implementation", I came across on an identity that I don't understand basically it says:
$$
d = mbox{Arg}left{inf_{d in W} I(d)right}.
$$

This expression came from the Euler type differential equation
$$
d(x) - l^2d''(x) = 0,
$$

which has the solution as an exponential function
$$
d(x) = exp(-|x|/l)
$$

Variational principle of this differential equation is ,
$$
d = mbox{Arg}left{inf_{d in W} I(d)right}.
$$

with $$ W = {d | d(0)=1, d(pm infty)=0}$$
where I(d) is a functional defined as an integral
$$
I(d) = frac{1}{2}int [d^2 + l^2d'^2] dV,
$$

and $l$ is a parameter.



Can anyone tell me what does that mean?










share|cite|improve this question











$endgroup$












  • $begingroup$
    Can you provide more context please? What is $I$? Maybe a function?
    $endgroup$
    – Dog_69
    Jan 17 at 9:42






  • 2




    $begingroup$
    Welcome to MSE. It is in your best interest that you type your questions (using MathJax) instead of posting links to pictures.
    $endgroup$
    – José Carlos Santos
    Jan 17 at 9:43










  • $begingroup$
    A pdf of the mentioned article is available here.
    $endgroup$
    – Mees de Vries
    Jan 17 at 9:47










  • $begingroup$
    It appears to simply be saying: find the infimum of the set $I(d)$ and return the argument, $d$, for the $I(d)$ that is the infimum.
    $endgroup$
    – Andy Walls
    Jan 17 at 13:20
















0












0








0





$begingroup$


I am currently studying the phase-field method for fracture modeling. In an article by Miehe -"Thermodynamically consistent phase-field models of fracture: Variational principles and multi-field FE implementation", I came across on an identity that I don't understand basically it says:
$$
d = mbox{Arg}left{inf_{d in W} I(d)right}.
$$

This expression came from the Euler type differential equation
$$
d(x) - l^2d''(x) = 0,
$$

which has the solution as an exponential function
$$
d(x) = exp(-|x|/l)
$$

Variational principle of this differential equation is ,
$$
d = mbox{Arg}left{inf_{d in W} I(d)right}.
$$

with $$ W = {d | d(0)=1, d(pm infty)=0}$$
where I(d) is a functional defined as an integral
$$
I(d) = frac{1}{2}int [d^2 + l^2d'^2] dV,
$$

and $l$ is a parameter.



Can anyone tell me what does that mean?










share|cite|improve this question











$endgroup$




I am currently studying the phase-field method for fracture modeling. In an article by Miehe -"Thermodynamically consistent phase-field models of fracture: Variational principles and multi-field FE implementation", I came across on an identity that I don't understand basically it says:
$$
d = mbox{Arg}left{inf_{d in W} I(d)right}.
$$

This expression came from the Euler type differential equation
$$
d(x) - l^2d''(x) = 0,
$$

which has the solution as an exponential function
$$
d(x) = exp(-|x|/l)
$$

Variational principle of this differential equation is ,
$$
d = mbox{Arg}left{inf_{d in W} I(d)right}.
$$

with $$ W = {d | d(0)=1, d(pm infty)=0}$$
where I(d) is a functional defined as an integral
$$
I(d) = frac{1}{2}int [d^2 + l^2d'^2] dV,
$$

and $l$ is a parameter.



Can anyone tell me what does that mean?







supremum-and-infimum






share|cite|improve this question















share|cite|improve this question













share|cite|improve this question




share|cite|improve this question








edited Jan 17 at 12:11









postmortes

2,04131119




2,04131119










asked Jan 17 at 9:37









Cro Simpson2.0Cro Simpson2.0

12




12












  • $begingroup$
    Can you provide more context please? What is $I$? Maybe a function?
    $endgroup$
    – Dog_69
    Jan 17 at 9:42






  • 2




    $begingroup$
    Welcome to MSE. It is in your best interest that you type your questions (using MathJax) instead of posting links to pictures.
    $endgroup$
    – José Carlos Santos
    Jan 17 at 9:43










  • $begingroup$
    A pdf of the mentioned article is available here.
    $endgroup$
    – Mees de Vries
    Jan 17 at 9:47










  • $begingroup$
    It appears to simply be saying: find the infimum of the set $I(d)$ and return the argument, $d$, for the $I(d)$ that is the infimum.
    $endgroup$
    – Andy Walls
    Jan 17 at 13:20




















  • $begingroup$
    Can you provide more context please? What is $I$? Maybe a function?
    $endgroup$
    – Dog_69
    Jan 17 at 9:42






  • 2




    $begingroup$
    Welcome to MSE. It is in your best interest that you type your questions (using MathJax) instead of posting links to pictures.
    $endgroup$
    – José Carlos Santos
    Jan 17 at 9:43










  • $begingroup$
    A pdf of the mentioned article is available here.
    $endgroup$
    – Mees de Vries
    Jan 17 at 9:47










  • $begingroup$
    It appears to simply be saying: find the infimum of the set $I(d)$ and return the argument, $d$, for the $I(d)$ that is the infimum.
    $endgroup$
    – Andy Walls
    Jan 17 at 13:20


















$begingroup$
Can you provide more context please? What is $I$? Maybe a function?
$endgroup$
– Dog_69
Jan 17 at 9:42




$begingroup$
Can you provide more context please? What is $I$? Maybe a function?
$endgroup$
– Dog_69
Jan 17 at 9:42




2




2




$begingroup$
Welcome to MSE. It is in your best interest that you type your questions (using MathJax) instead of posting links to pictures.
$endgroup$
– José Carlos Santos
Jan 17 at 9:43




$begingroup$
Welcome to MSE. It is in your best interest that you type your questions (using MathJax) instead of posting links to pictures.
$endgroup$
– José Carlos Santos
Jan 17 at 9:43












$begingroup$
A pdf of the mentioned article is available here.
$endgroup$
– Mees de Vries
Jan 17 at 9:47




$begingroup$
A pdf of the mentioned article is available here.
$endgroup$
– Mees de Vries
Jan 17 at 9:47












$begingroup$
It appears to simply be saying: find the infimum of the set $I(d)$ and return the argument, $d$, for the $I(d)$ that is the infimum.
$endgroup$
– Andy Walls
Jan 17 at 13:20






$begingroup$
It appears to simply be saying: find the infimum of the set $I(d)$ and return the argument, $d$, for the $I(d)$ that is the infimum.
$endgroup$
– Andy Walls
Jan 17 at 13:20












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%2f3076785%2fwhat-does-arg-inf-id-means%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%2f3076785%2fwhat-does-arg-inf-id-means%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

How to fix TextFormField cause rebuild widget in Flutter

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