Explicit dynamical properties of the Pelikan random map in the chaotic region and at the intermittent critical point towards the non-chaotic region
Cecile Monthus
TL;DR
This work analyzes the Pelikan random map, a random mixture of a chaotic doubling map and a non-chaotic half-contraction, by developing two complementary frameworks: a closed density-subspace perspective leading to a Markov chain with resetting and a binary-decomposition perspective yielding two global variables $z_t$ and $F_t$. It derives explicit stationary states, finite-time propagators, first-passage-time distributions, and spectral decompositions, with precise chaotic-region and critical-point scalings, including large-deviation rate functions for additive observables. The results illuminate how resetting and conditioning shape relaxation, rare events, and time correlations across chaotic, non-chaotic, and critical regimes, enabling exact characterizations of convergence, excursion dynamics, and density fluctuations in this paradigmatic random-dynamics model. The insights have broad relevance for non-equilibrium statistical physics, intermittent dynamics, and stochastic processes with resetting, offering exact benchmarks for similar systems and informing the design of analytic techniques for complex dynamical maps.
Abstract
The Pelikan random trajectories $x_t \in [0,1[$ are generated by choosing the chaotic doubling map $x_{t+1}=2 x_t [mod 1]$ with probability $p$ and the non-chaotic half-contracting map $x_{t+1}=\frac{x_t}{2}$ with probability $(1-p)$. We compute various dynamical observables as a function of the parameter $p$ via two perspectives. In the first perspective, we focus on the closed dynamics within the subspace of probability densities that remain constant on the binary-intervals $x \in [ 2^{-n-1}, 2^{-n}[$ partitioning the interval $x \in [0,1[$ : the dynamics for the weights $π_t(n)$ of these intervals corresponds to a biased random walk on the half-infinite lattice $n \in \{0,1,2,..+\infty\}$ with resetting occurring with probability $p$ from the origin $n=0$ towards any site $n$ drawn with the distribution $2^{-n-1}$. In the second perspective, we study the Pelikan dynamics for any initial condition $x_0$ via the binary decomposition $x_t = \sum_{l=1}^{+\infty} \frac{σ_l (t)}{2^l} $, where the dynamics for the half-infinite lattice $l=1,2,..$ of the binary variables $σ_l(t) \in \{0,1\}$ can be reformulated in terms of two global variables : $z_t$ corresponds to a biased random walk on the half-infinite lattice $z \in \{0,1,2,..+\infty\}$ that may remain at the origin $z=0$ with probability $p$, while $F_t \in \{0,1,2,..t\}$ counts the number of time-steps $τ\in [0,t-1]$ where $z_{τ+1}=0=z_τ$ and represents the number of the binary coefficients of the initial condition that have been erased. We discuss typical and large deviations properties in the chaotic region $\frac{1}{2}<p<1 $ as well as at the intermittent critical point $p_c=\frac{1}{2}$ towards the non-chaotic region $0<p<\frac{1}{2}$.
