Smooth

From Maths
Revision as of 06:38, 7 April 2015 by Alec (Talk | contribs)

(diff) ← Older revision | Latest revision (diff) | Newer revision → (diff)
Jump to: navigation, search

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