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Dec 6, 2023 at 15:48 history edited Qmechanic CC BY-SA 4.0
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Nov 1, 2016 at 0:07 vote accept Milou
Oct 14, 2016 at 13:38 answer added Qmechanic timeline score: 4
Oct 14, 2016 at 13:38 history edited Qmechanic CC BY-SA 3.0
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Oct 2, 2016 at 16:40 comment added Milou What I've written in my comment is absolutely wrong :) I'm sorry! So I've decided to use the Ostogradsky Hamiltonian. But I still don't know if the Hamilton-jacobi equation is still true anyway.
Sep 30, 2016 at 17:55 comment added ACuriousMind The point is - what space is that new $H$ living on? In the first-order setting, we switch from the Lagrangian tangent bundle with coordinates $(q,\dot{q})$ to the Hamiltonian phase space/cotangent bundle with coordinates $(q,p)$. But here you can't just Legendre transform the $\dot{q}$, you need to somehow handle the $\ddot{q}$ dependence. There are difference schemes for that, leading to different notions of the final Hamiltonian, so it's not exactly clear what you want to do here.
Sep 30, 2016 at 17:47 comment added Milou @ACuriousMind am I allowed to write this? I've never worked with a higher-order L.
Sep 30, 2016 at 1:39 comment added Milou umm if it's true to consider that ∂S/∂t=−H, I would define my Hamiltonian from \delta S (wich is equal to L \delta t), so H will be =∑j p\dot{q}+∑j ∂S/∂\dot{q} \ddot{q}−L (all will j index)
Sep 30, 2016 at 1:26 comment added ACuriousMind Which definition of the "Hamiltonian" are you using for higher-order Lagrangians? There are several (e.g. that by Ostrogradsky) that are similar, but not the same.
Sep 30, 2016 at 1:13 history edited Milou
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Sep 29, 2016 at 20:11 history asked Milou CC BY-SA 3.0