Why the Hamiltonian is constant along the integral curves of the hamiltonian vector field?
$begingroup$
Let $H$ the Hamiltonian of a system and $gamma $ an integral curve of the Hamiltonian vector field, i.e. if $gamma (t)=(q(t),p(t))$ and $H(p,q)$ is the Hamiltonian, then $$begin{cases} dot p=-H_q\ dot q= H_pend{cases}.$$
In wikipedia the say that $H$ is constant along $gamma $. Why is this true ? i.e. why $H(gamma (t))$ is constant ?
symplectic-geometry
$endgroup$
add a comment |
$begingroup$
Let $H$ the Hamiltonian of a system and $gamma $ an integral curve of the Hamiltonian vector field, i.e. if $gamma (t)=(q(t),p(t))$ and $H(p,q)$ is the Hamiltonian, then $$begin{cases} dot p=-H_q\ dot q= H_pend{cases}.$$
In wikipedia the say that $H$ is constant along $gamma $. Why is this true ? i.e. why $H(gamma (t))$ is constant ?
symplectic-geometry
$endgroup$
add a comment |
$begingroup$
Let $H$ the Hamiltonian of a system and $gamma $ an integral curve of the Hamiltonian vector field, i.e. if $gamma (t)=(q(t),p(t))$ and $H(p,q)$ is the Hamiltonian, then $$begin{cases} dot p=-H_q\ dot q= H_pend{cases}.$$
In wikipedia the say that $H$ is constant along $gamma $. Why is this true ? i.e. why $H(gamma (t))$ is constant ?
symplectic-geometry
$endgroup$
Let $H$ the Hamiltonian of a system and $gamma $ an integral curve of the Hamiltonian vector field, i.e. if $gamma (t)=(q(t),p(t))$ and $H(p,q)$ is the Hamiltonian, then $$begin{cases} dot p=-H_q\ dot q= H_pend{cases}.$$
In wikipedia the say that $H$ is constant along $gamma $. Why is this true ? i.e. why $H(gamma (t))$ is constant ?
symplectic-geometry
symplectic-geometry
asked Jan 11 at 15:53
user623855user623855
1507
1507
add a comment |
add a comment |
1 Answer
1
active
oldest
votes
$begingroup$
For $H(p,q,t) = H(p(t),q(t))$ think that
$$
frac{d}{dt}H(p(t),q(t)) = H_p dot p + H_q dot q
$$
$endgroup$
$begingroup$
Indeed, it make sense :) But I'm confusion with wikipedia notation, what they mean by $<dH,dot gamma >=0$ ? Because $omega $ is not a scalar product (is not a riemann manifold)
$endgroup$
– user623855
Jan 11 at 16:03
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%2f3069995%2fwhy-the-hamiltonian-is-constant-along-the-integral-curves-of-the-hamiltonian-vec%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
$begingroup$
For $H(p,q,t) = H(p(t),q(t))$ think that
$$
frac{d}{dt}H(p(t),q(t)) = H_p dot p + H_q dot q
$$
$endgroup$
$begingroup$
Indeed, it make sense :) But I'm confusion with wikipedia notation, what they mean by $<dH,dot gamma >=0$ ? Because $omega $ is not a scalar product (is not a riemann manifold)
$endgroup$
– user623855
Jan 11 at 16:03
add a comment |
$begingroup$
For $H(p,q,t) = H(p(t),q(t))$ think that
$$
frac{d}{dt}H(p(t),q(t)) = H_p dot p + H_q dot q
$$
$endgroup$
$begingroup$
Indeed, it make sense :) But I'm confusion with wikipedia notation, what they mean by $<dH,dot gamma >=0$ ? Because $omega $ is not a scalar product (is not a riemann manifold)
$endgroup$
– user623855
Jan 11 at 16:03
add a comment |
$begingroup$
For $H(p,q,t) = H(p(t),q(t))$ think that
$$
frac{d}{dt}H(p(t),q(t)) = H_p dot p + H_q dot q
$$
$endgroup$
For $H(p,q,t) = H(p(t),q(t))$ think that
$$
frac{d}{dt}H(p(t),q(t)) = H_p dot p + H_q dot q
$$
edited Jan 11 at 16:11
answered Jan 11 at 16:01
CesareoCesareo
8,6793516
8,6793516
$begingroup$
Indeed, it make sense :) But I'm confusion with wikipedia notation, what they mean by $<dH,dot gamma >=0$ ? Because $omega $ is not a scalar product (is not a riemann manifold)
$endgroup$
– user623855
Jan 11 at 16:03
add a comment |
$begingroup$
Indeed, it make sense :) But I'm confusion with wikipedia notation, what they mean by $<dH,dot gamma >=0$ ? Because $omega $ is not a scalar product (is not a riemann manifold)
$endgroup$
– user623855
Jan 11 at 16:03
$begingroup$
Indeed, it make sense :) But I'm confusion with wikipedia notation, what they mean by $<dH,dot gamma >=0$ ? Because $omega $ is not a scalar product (is not a riemann manifold)
$endgroup$
– user623855
Jan 11 at 16:03
$begingroup$
Indeed, it make sense :) But I'm confusion with wikipedia notation, what they mean by $<dH,dot gamma >=0$ ? Because $omega $ is not a scalar product (is not a riemann manifold)
$endgroup$
– user623855
Jan 11 at 16:03
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%2f3069995%2fwhy-the-hamiltonian-is-constant-along-the-integral-curves-of-the-hamiltonian-vec%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