From: Christophe Guyeux Date: Thu, 8 Sep 2011 14:26:45 +0000 (+0200) Subject: Nouveau théorème ajouté X-Git-Url: https://bilbo.iut-bm.univ-fcomte.fr/and/gitweb/prng_gpu.git/commitdiff_plain/716f5cce1f0b4cef3c6dfe87f218f6ad04d0ab97?ds=inline Nouveau théorème ajouté --- diff --git a/prng_gpu.tex b/prng_gpu.tex index cd8bad3..6ebbcd9 100644 --- a/prng_gpu.tex +++ b/prng_gpu.tex @@ -85,6 +85,26 @@ Let $x \in \mathcal{X}$ and $V \in \mathcal{V}_\tau (x)$ a $\tau-$neighborhood o But $\tau \subset \tau'$, so $\omega \in \tau'$, and then $V \in \mathcal{V}_{\tau'} (x)$. As $(\mathcal{X}_{\tau'},f)$ is regular, there is a periodic point for $f$ into $V$, and the regularity of $(\mathcal{X}_\tau,f)$ is proven. \end{proof} +\subsection{A given system can always be claimed as chaotic} + +Let $f$ an iteration function on $\mathcal{X}$ having at least a fixed point. Then this function is chaotic (in a certain way): + +\begin{theorem} +Let $\mathcal{X}$ a nonempty set and $f: \mathcal{X} \to \X$ a function having at least a fixed point. +Then $f$ is $\tau_0-$chaotic, where $\tau_0$ is the trivial (indiscrete) topology on $\X$. +\end{theorem} + + +\begin{proof} +$f$ is transitive when $\forall \omega, \omega' \in \tau_0 \setminus \{\varnothing\}, \exists n \in \mathds{N}, f^{(n)}(\omega) \cap \omega' \neq \varnothing$. +As $\tau_0 = \left\{ \varnothing, \X \right\}$, this is equivalent to look for an integer $n$ s.t. $f^{(n)}\left( \X \right) \cap \X \neq \varnothing$. For instance, $n=0$ is appropriate. + +Let us now consider $x \in \X$ and $V \in \mathcal{V}_{\tau_0} (x)$. Then $V = \mathcal{X}$, so $V$ has at least a fixed point for $f$. Consequently $f$ is regular, and the result is established. +\end{proof} + + + +