Difference between revisions of "Smooth"

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(Created page with "'''Note:''' there are many definitions of smooth and it changes a lot between books - I shall be consistent in this wiki and mention the others ==Definition== Here {{M|U\subs...")
 
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==Warning about diffeomorphisms==
 
==Warning about diffeomorphisms==
A {{M|F}} is a diffeomorphism if it is bijective, smooth and the inverse {{M|F^{-1} }} is also smooth.
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A {{M|F}} is a [[Diffeomorphism]] if it is bijective, smooth and the inverse {{M|F^{-1} }} is also smooth.
  
 
==References==
 
==References==

Latest revision as of 06:38, 7 April 2015

Note: there are many definitions of smooth and it changes a lot between books - I shall be consistent in this wiki and mention the others

Definition

Here [ilmath]U\subseteq\mathbb{R}^n[/ilmath] is open, and [ilmath]V\subseteq\mathbb{R}^m[/ilmath] is also open, we say a function[1] [math]F:U\rightarrow V[/math] is smooth, [math]C^\infty[/math] or infinitely differentiable if:

  • Each component function ([ilmath]F^i[/ilmath] for [ilmath]1\le i\le m\in\mathbb{N} [/ilmath] has continuous partial derivatives of all orders

TODO: Expand this to a more formal one - like the one from Loring W. Tu's book



Warning about diffeomorphisms

A [ilmath]F[/ilmath] is a Diffeomorphism if it is bijective, smooth and the inverse [ilmath]F^{-1} [/ilmath] is also smooth.

References

  1. John M Lee - Introduction to smooth manifolds - Second Edition