Timeline for Why is the standard contact structure on $\mathbb R^{2n+1}$ called "standard"?
Current License: CC BY-SA 4.0
8 events
when toggle format | what | by | license | comment | |
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Dec 1, 2020 at 23:44 | vote | accept | boink | ||
Dec 1, 2020 at 23:43 | vote | accept | boink | ||
Dec 1, 2020 at 23:44 | |||||
Dec 1, 2020 at 17:36 | comment | added | Andy Sanders | Forgiving historical inaccuracies (and perhaps eliding constants), I would wager it has something to do with the restriction of the (canonical) Liouville one form on $T^{*}\mathbb{R}^{n}$ to the unit co-sphere bundle with respect to the Euclidean metric on $\mathbb{R}^{n}.$ | |
Dec 1, 2020 at 9:13 | answer | added | Marco Golla | timeline score: 4 | |
Dec 1, 2020 at 9:03 | answer | added | Thomas Rot | timeline score: 4 | |
Dec 1, 2020 at 5:42 | comment | added | Panagiotis Konstantis | Like in symplectic geometry, there is a Darboux theorem in contact geometry, which tells you that on a manifold with contact structure there is always a chart such that the given contact structure looks like the standard contact structure on $\mathbb R^n$. | |
Dec 1, 2020 at 4:56 | comment | added | Deane Yang | Given a function $f: \mathbb{R}^n \rightarrow \mathbb{R}$, consider the graph of f and its gradient, $G = \{ (x_1, \partial_1f, \dots, x_n,\partial_nf, f) \}$. The standard contact form $\alpha$ vanishes when restricted to this graph. Conversely, any $n$-dimensional submanifold on which $\alpha$ vanishes but the $n$-form $dx_1 \wedge\cdots\wedge dx_n \ne 0$ at every point is the graph of a function and its gradient. This is how the concept of a contact structure first arose. | |
Dec 1, 2020 at 4:51 | history | asked | boink | CC BY-SA 4.0 |