PlanetMath (more info)
 Math for the people, by the people. Sponsor PlanetMath
Encyclopedia | Requests | Forums | Docs | Wiki | Random | RSS  
Login
create new user
name:
pass:
forget your password?
Main Menu
Revision difference : Axiom A
Version current Version 3
\PMlinkescapeword{satisfies} \PMlinkescapeword{satisfies}
Let $M$ be a smooth manifold. We say that a diffeomorphism $f\colon M\to M$ satisfies Let $M$ be a smooth manifold. We say that a diffeomorphism $f\colon M\to M$ satisfies
(Smale's) \emph{Axiom A} (or that $f$ is an Axiom A diffeomorphism) if (Smale's) \emph{Axiom A} (or that $f$ is an Axiom A diffeomorphism) if
\begin{enumerate} \begin{enumerate}
\item the nonwandering set $\Omega(f)$ has a hyperbolic structure; \item the nonwandering set $\Omega(f)$ has a hyperbolic structure;
\item the set of periodic points of $f$ is dense in $\Omega(f)$: $\overline{\Per(f)} = \Omega(f)$. \item the set of periodic points of $f$ is dense in $\Omega(f)$: $\overline{\Per(f)} = \Omega(f)$.
\end{enumerate} \end{enumerate}
Sometimes, Axiom A diffeomorphisms are called hyperbolic diffeomorphisms, because the portion of $M$ where the ``interesting'' dynamics occur (namely, $\Omega(f)$) has a hyperbolic behaviour.