Skip to main content

Timeline for Cotangent bundle lift theorem

Current License: CC BY-SA 4.0

13 events
when toggle format what by license comment
Jan 17, 2022 at 1:31 history edited Martin Sleziak CC BY-SA 4.0
a minor typo
Jan 16, 2022 at 19:08 comment added JHM @glS You are correct I wrote composition in the wrong order, thank you for clarifying! I was trying to say $d\pi \circ d(f^*)=df \circ d\pi$, as per the commutative diagram $f \circ \pi = \pi \circ f^*$. But rereading my answer, I dont think I fully understood the question when I wrote it.
Jan 16, 2022 at 19:04 history edited JHM CC BY-SA 4.0
deleted 16 characters in body
Jan 16, 2022 at 18:49 comment added glS isn't $d(f^*)\circ d\pi$ ill-defined here? We have $\pi:T^* M\to M$, thus $d\pi:TT^* M\to TM$, but $d(f^*): TT^*M\to TT^* M$. So $d(f^*)$ takes as input elements of $TT^*M$ while $d\pi$ outputs elements of $TM$. Same for $d\pi\circ df$: $df$ gives things in $TM$ wihle $d\pi$ wants things in $TT^* M$. Am I misunderstanding something? The relation makes more sense if written as $d\pi\circ d(f^*)=df^{-1}\circ d\pi$, I think, which should follow from $f^{-1}\circ \pi=\pi\circ f^*$, due to $f^*(\alpha_p)\equiv\alpha_p\circ df|_{f^{-1}(p)}\in T^*_{f^{-1}(p)}M$ if $\alpha_p\in T_p^*M$.
Dec 8, 2013 at 0:47 vote accept Pengfei
Dec 8, 2013 at 0:47 comment added Pengfei I checked the reference provided by alvarezpaiva. By considering the symplectic vector field induced by $\theta$, such $F$ must preserve the fibers. The pullback relation gives $\pi\circ F=f^{-1}\circ \pi$, which is used to prove $f^\ast\theta=\theta$. There is another typo at the end of the second paragraph: $\pi\circ G=\pi$. Now I understand your answer. Thank you!
S Dec 7, 2013 at 19:42 history suggested hoj201 CC BY-SA 3.0
If $G:T^*M \to T^*M$ is a fiber map over the identity when $\pi \circ G = \pi$. I think you wrote $dG \circ d\pi = d\pi$ when you meant to write $d\pi \circ dG = d\pi$. Also a parenthesis was missing.
Dec 7, 2013 at 18:48 review Suggested edits
S Dec 7, 2013 at 19:42
Dec 7, 2013 at 5:01 history edited JHM CC BY-SA 3.0
minor re-wording
Dec 7, 2013 at 4:54 history edited JHM CC BY-SA 3.0
minor wording
Dec 7, 2013 at 4:33 history undeleted JHM
Dec 7, 2013 at 4:00 history deleted JHM via Vote
Dec 7, 2013 at 3:14 history answered JHM CC BY-SA 3.0