Exponential map (discrete dynamical systems)

Parameter plane of the complex exponential family f(z)=exp(z)+c with 8 external ( parameter) rays

In the theory of dynamical systems, the exponential map can be used as the evolution function of the discrete nonlinear dynamical system.[1]

Family

The family of exponential functions is called the exponential family.

Forms

There are many forms of these maps,[2] many of which are equivalent under a coordinate transformation. For example two of the most common ones are:

• $\displaystyle{ E_c : z \to e^z + c }$
• $\displaystyle{ E_\lambda : z \to \lambda * e^z }$

The second one can be mapped to the first using the fact that $\displaystyle{ \lambda * e^z. = e^{z+ln(\lambda)} }$, so $\displaystyle{ E_\lambda : z \to e^z + ln(\lambda) }$ is the same under the transformation $\displaystyle{ z=z+ln(\lambda) }$. The only difference is that, due to multi-valued properties of exponentiation, there may be a few select cases that can only be found in one version. Similar arguments can be made for many other formulas.