Stability of a linear equation
$begingroup$
If $A$ is a matrix, then $e^{At} leq C e^{-lambda t}$ if and only if the spectrum of $A$ consists of eigenvalues with negative real parts.
Is there a similar result, relating stability to the spectrum, when $A$ is a non-selfadjoint operator, when $e^{-At}$ is interpreted as the solution to
$$frac{partial u}{partial t} = - A u,$$
with appropriate boundary conditions? I assume that there is, but I haven't been able to find a reference.
operator-theory stability-theory
$endgroup$
add a comment |
$begingroup$
If $A$ is a matrix, then $e^{At} leq C e^{-lambda t}$ if and only if the spectrum of $A$ consists of eigenvalues with negative real parts.
Is there a similar result, relating stability to the spectrum, when $A$ is a non-selfadjoint operator, when $e^{-At}$ is interpreted as the solution to
$$frac{partial u}{partial t} = - A u,$$
with appropriate boundary conditions? I assume that there is, but I haven't been able to find a reference.
operator-theory stability-theory
$endgroup$
add a comment |
$begingroup$
If $A$ is a matrix, then $e^{At} leq C e^{-lambda t}$ if and only if the spectrum of $A$ consists of eigenvalues with negative real parts.
Is there a similar result, relating stability to the spectrum, when $A$ is a non-selfadjoint operator, when $e^{-At}$ is interpreted as the solution to
$$frac{partial u}{partial t} = - A u,$$
with appropriate boundary conditions? I assume that there is, but I haven't been able to find a reference.
operator-theory stability-theory
$endgroup$
If $A$ is a matrix, then $e^{At} leq C e^{-lambda t}$ if and only if the spectrum of $A$ consists of eigenvalues with negative real parts.
Is there a similar result, relating stability to the spectrum, when $A$ is a non-selfadjoint operator, when $e^{-At}$ is interpreted as the solution to
$$frac{partial u}{partial t} = - A u,$$
with appropriate boundary conditions? I assume that there is, but I haven't been able to find a reference.
operator-theory stability-theory
operator-theory stability-theory
asked Jan 12 at 18:24
Roberto RastapopoulosRoberto Rastapopoulos
896424
896424
add a comment |
add a comment |
1 Answer
1
active
oldest
votes
$begingroup$
You need some assumptions on $A$ to have a unique solution of the evolution equation (and one should also talk about the type of solution). Anyway, I think the answer to your question lies in the Hille-Yosida theorem:
If $A$ is the generator of the strongly continuous semigroup $T$, then $|T(t)|leq M e^{omega t}$ if and only if the spectrum of $A$ is contained in the half-plane ${zinmathbb{C}mid operatorname{Re}zleq omega}$.
In this case $u(t)=T(t)x$ is the unique mild solution of the initial value problem
begin{align*}
dot u(t)&=Au(t),\
u(0)&=x.
end{align*}
The Hille-Yosida theorem also gives a characterization of the operator that generate strongly continuous semigroups.
$endgroup$
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%2f3071222%2fstability-of-a-linear-equation%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 need some assumptions on $A$ to have a unique solution of the evolution equation (and one should also talk about the type of solution). Anyway, I think the answer to your question lies in the Hille-Yosida theorem:
If $A$ is the generator of the strongly continuous semigroup $T$, then $|T(t)|leq M e^{omega t}$ if and only if the spectrum of $A$ is contained in the half-plane ${zinmathbb{C}mid operatorname{Re}zleq omega}$.
In this case $u(t)=T(t)x$ is the unique mild solution of the initial value problem
begin{align*}
dot u(t)&=Au(t),\
u(0)&=x.
end{align*}
The Hille-Yosida theorem also gives a characterization of the operator that generate strongly continuous semigroups.
$endgroup$
add a comment |
$begingroup$
You need some assumptions on $A$ to have a unique solution of the evolution equation (and one should also talk about the type of solution). Anyway, I think the answer to your question lies in the Hille-Yosida theorem:
If $A$ is the generator of the strongly continuous semigroup $T$, then $|T(t)|leq M e^{omega t}$ if and only if the spectrum of $A$ is contained in the half-plane ${zinmathbb{C}mid operatorname{Re}zleq omega}$.
In this case $u(t)=T(t)x$ is the unique mild solution of the initial value problem
begin{align*}
dot u(t)&=Au(t),\
u(0)&=x.
end{align*}
The Hille-Yosida theorem also gives a characterization of the operator that generate strongly continuous semigroups.
$endgroup$
add a comment |
$begingroup$
You need some assumptions on $A$ to have a unique solution of the evolution equation (and one should also talk about the type of solution). Anyway, I think the answer to your question lies in the Hille-Yosida theorem:
If $A$ is the generator of the strongly continuous semigroup $T$, then $|T(t)|leq M e^{omega t}$ if and only if the spectrum of $A$ is contained in the half-plane ${zinmathbb{C}mid operatorname{Re}zleq omega}$.
In this case $u(t)=T(t)x$ is the unique mild solution of the initial value problem
begin{align*}
dot u(t)&=Au(t),\
u(0)&=x.
end{align*}
The Hille-Yosida theorem also gives a characterization of the operator that generate strongly continuous semigroups.
$endgroup$
You need some assumptions on $A$ to have a unique solution of the evolution equation (and one should also talk about the type of solution). Anyway, I think the answer to your question lies in the Hille-Yosida theorem:
If $A$ is the generator of the strongly continuous semigroup $T$, then $|T(t)|leq M e^{omega t}$ if and only if the spectrum of $A$ is contained in the half-plane ${zinmathbb{C}mid operatorname{Re}zleq omega}$.
In this case $u(t)=T(t)x$ is the unique mild solution of the initial value problem
begin{align*}
dot u(t)&=Au(t),\
u(0)&=x.
end{align*}
The Hille-Yosida theorem also gives a characterization of the operator that generate strongly continuous semigroups.
answered Jan 15 at 13:01
MaoWaoMaoWao
2,853617
2,853617
add a comment |
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%2f3071222%2fstability-of-a-linear-equation%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