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Jun 29, 2022 at 8:24 vote accept ychemama
Jun 27, 2022 at 23:43 answer added Josh Lackman timeline score: 2
Jul 23, 2018 at 15:41 answer added Ben McKay timeline score: 6
Jul 23, 2018 at 15:13 history bumped CommunityBot This question has answers that may be good or bad; the system has marked it active so that they can be reviewed.
Jun 23, 2018 at 17:25 comment added Peter Michor See mathoverflow.net/a/116487/26935 and other answers there for some aspects.
Jun 23, 2018 at 15:13 answer added Alex Gavrilov timeline score: 0
Jun 22, 2018 at 18:13 comment added Ivan Izmestiev Then a possible approach to this could be by "natural operations", see for example the book "Natural operations in differential geometry" by Kolar, Michor, and Slovak. I would guess that any tensor "constructed out of $\nabla$" depends only on the curvature of $\nabla$.
Jun 22, 2018 at 11:58 comment added ychemama @IvanIzmestiev I know that the usual definition cannot be extended as such. My question is : why there is no more general notion of torsion which applies to any vector bundle? Or is there ? Or to put it anther way : is the curvature the only tensor field which can be constructed out a connection $\nabla$ ?
Jun 22, 2018 at 11:28 comment added Ivan Izmestiev The definition of the torsion tensor $T(X,Y) = \nabla_X Y - \nabla_Y X - [X,Y]$ cannot be extended to arbitrary vector bundles: $\nabla_X Y$ subsumes $X \in \Gamma(TM)$ and $Y \in \Gamma(E)$, and then you exchange $X$ and $Y$... When you speak about "the twist of a moving frame along a curve", don't you mean a different notion of torsion, like in Frenet-Serret formulas?
Jun 22, 2018 at 10:22 history asked ychemama CC BY-SA 4.0