Emergence of Planck’s Constant from Iterated Maps

Iterations of continuous maps are the simplest models of generic dynamical systems. In particular, circle maps display several key properties of complex dynamics, such as phase-locking and the quasi-periodicity route to chaos. Our work points out that Planck’s constant may be derived from the scaling behavior of circle maps in the asymptotic limit.

The Image Size of Iterated Rational Maps over Finite Fields

Let $\varphi : {{\mathbb{P}}}^1( {{\mathbb{F}}}_q)\to{{\mathbb{P}}}^1( {{\mathbb{F}}}_q)$ be a rational map of degree $d>1$ on a fixed finite field. We give asymptotic formulas for the size of image sets $\varphi ^n( {{\mathbb{P}}}^1( {{\mathbb{F}}}_q))$ as a function of $n$. This is done using properties of Galois groups of iterated maps, whose connection to the size of image sets is established via the Chebotarev Density Theorem. We apply our results in the following setting. For a rational map defined over a number field, consider the reduction of the map modulo each prime of the number field. We use our results to give explicit bounds on the proportion of periodic points in the residue fields.