Rational map associated with the Sigmoid Beverton-Holt model on the projective line over $\mathbb{Q}_p$
Cheng Liu
TL;DR
The paper addresses the $p$-adic dynamics of the Sigmoid Beverton-Holt model on the projective line over $\mathbb{Q}_p$ by reducing the rational map to the polynomial map $f_N(x)=\frac{x^N+1}{a}$ via a topological conjugacy, enabling a comprehensive analysis without the gcd$(N,p)$ constraint. It then classifies the dynamics across the regimes $|a|_p>1$, $|a|_p<1$, and $|a|_p=1$, using minimal decomposition and $p$-adic repeller theory to obtain fixed-point structures, invariant sets, and, in many cases, conjugacies to shift spaces. The main contributions include explicit descriptions of asymptotic behavior, fixed points, and minimal invariant sets (with detailed $p=2$ and $p=3$ treatments) and a systematic reduction of rational dynamics to polynomial dynamics. This work advances the understanding of $p$-adic dynamical systems for biologically motivated models and demonstrates the effectiveness of minimal decomposition and shift-space conjugacies in resolving the long-term behavior of seemingly complex $p$-adic maps.
Abstract
We describe the dynamical structure of the $p$-adic rational dynamical systems associated with the Sigmoid Beverton-Holt model on the projective line over the field $\mathbb{Q}_p$ of $p$-adic numbers. Our methods are minimal decomposition of $p$-adic polynomials with coefficients in $\mathbb{Z}_p$ established by Fan and Liao and the chaotic description of $p$-adic repellers of Fan, Liao, Wang and Zhou.
