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May
31
comment Car movement - differential geometry interpretation.
Dear jkersch: it could be helpful for someone starting to learn analysis on manifolds, to see the product formula (cf. for example Abraham, Marsden, Ratiu MTA) as justification of the interpretation you give of the Lie bracket of vector fields. I believe that this interpretation is not always presented in introductory texts to smooth manifolds.
May
30
comment Kernel of a bundle map
Dear Benjamin: Please, Martin and Daniel's remarks, however objectionable, are directed exclusively to the question, and not at all to the questioner.
May
30
revised Sobolev space: probably simple ode…
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May
30
comment How to prove that a certain action is hamiltonian?
@Robert Bryant: Thank you very much for the attention, and the careful historical information. I did not known exactly where, in the work of Elie Cartan, this formula appeared for the first time. Please, my previous observation was just an hypothesis to explain the attribution of this formula to Henri instead than to Elie, as I found it sometimes in the literature.
May
29
comment How to prove that a certain action is hamiltonian?
@Theo Buehler: Yes surely it is due to the foundational work of Elié Cartan, but I thought it was named after his son Henri Cartan, for this formula is singled out in his axiomatic presentation of the equivariant cohomology for smooth manifolds acted by a Lie group. Precisely, I found it under this name in Symplectic Geometry and Analytical Mechanics of Libermann and Marle. Thanks again for your help with editing and for your suggestion about LaTeX.
May
29
comment How to prove that a certain action is hamiltonian?
@Theo Buehler: Thanks a lot.
May
29
comment How to prove that a certain action is hamiltonian?
Please, excuse me, even if I exactly copied the text of the quoted question, here I have some difficulties in visualizing the sketched proof. Do you have the same troubles?
May
29
revised How to prove that a certain action is hamiltonian?
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May
29
revised How to prove that a certain action is hamiltonian?
trying to correct tex; deleted 5 characters in body
May
29
asked How to prove that a certain action is hamiltonian?
May
26
revised Proof of Upper bound of price of anarchy in local connection game
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May
24
revised A mass spring model for hair simulation
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May
23
revised What are “perfectoid spaces”?
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May
22
revised The $ Pic ^ 0 $ of an abelian variety
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May
22
comment $D_X$ algebras, $D_X$ schemes, connections
I supposed Beilinson Drinfeld Chiral Algebras ams.org/bookstore-getitem/item=COLL-51
May
17
revised What is a good way to think about a fundamental field on a principal G-bundle?
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May
17
revised What is a good way to think about a fundamental field on a principal G-bundle?
added 518 characters in body; added 2 characters in body
May
17
answered What is a good way to think about a fundamental field on a principal G-bundle?
May
12
revised Periodic orbits of Hamiltonian systems
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May
12
revised Periodic orbits of Hamiltonian systems
inserted a link, and quoted a theorem