Quadratic discrete dynamics associated to quadratic maps in the plane

Abstract

Dynamical systems allow one to model many phenomena, not only in Physics and Mathematics, but also in Biology, Engineering, Economics, etc. A bidimensional discrete dynamical system consists in iterating a mapping $f\colon \mathbb{R}^2\to \mathbb{R}^2$. The evolution of a point $p\in \mathbb{R}^2$ is described by the sequence of its iterated points, i.e.,$f^{n}(p)=f(f^{n-1}(p)),\dotsc,$ $n=0$, $n=1$, $n=2,\dotsc,$ showing the state of $p$ at the times $t=0,t=1,t=2,\dotsc,t=n$, etc. Such sequences replace the flux of a vector field in a continuous system and they are the object of Discrete Dynamics. The best known bidimensional discrete dynamical systems are the quadratic ones. In order to study them it is important to work with normal forms. This is achieved by means of invariants, which is a function depending on the system parameters remaining unchanged when a change of coordinates, is made. We study the fractal associated to any bidimensional regular homogeneous quadratic system (each of these terms defined below), which is the analogous to the Mandelbrot fractal associated to the map $z=x+yi\mapsto z^2$.