biology daily - the biology and biochemistry encyclopedia
biology daily articles and research Encyclopedia Dictionary Forums biology research links Weblinks Pictures Articles Blogs Newsletter

Artin-Mazur zeta function

In mathematics, the Artin-Mazur zeta function is a tool for studying the iterated functions that occur in dynamical systems and fractals.

It is defined as the formal power series

\zeta_f(z)=\exp \sum_{n=1}^\infty \textrm{card}  \left(\textrm{Fix} (f^n)\right) \frac {z^n}{n},

where Fix(fn) is the set of fixed points of the n-th iterate of an iterated function f, and \textrm{card}  \left(\textrm{Fix} (f^n)\right) is the cardinality of this set of fixed points.

Note that the zeta is defined only if set of fixed points is finite. This definition is formal in that it does not always have a positive radius of convergence.

The Artin-Mazur zeta-function is invariant under topological conjugation .

The Milnor-Thurston theorem states that the Artin-Mazur zeta function is the inverse of the kneading determinant of f.

The Artin-Mazur zeta is equivalent to the Weil zeta function when there is a diffeomorphism on a compact manifold.

Under certain cases, the Artin-Mazur zeta can be related to the Ihara zeta function of a graph.

See also

References



07-14-2008 23:18:10
The contents of this article are licensed from Wikipedia.org under the GNU Free Documentation License. How to see transparent copy
BiologyDaily.com 2005. Legal info   Privacy