Locating critical points attracted to p-adic attracting cycles
Juan Rivera-Letelier
TL;DR
This work analyzes non-Archimedean rational dynamics and establishes a sharp threshold for when an attracting cycle must attract a critical point. The authors introduce a d-dependant multiplier bound via ${\lambda(d)=\min\{|m|: m\in\{1,\dots,d\}\}}$ and show that a cycle with ${|\lambda|<\lambda(d)^{\#\mathcal{O}}}$ guarantees a nearby critical point, with Lyapunov exponents providing a finiteness criterion for small-exponent cycles. They develop a robust toolkit around distorted log-size and inseparability, proving refined bounds for locating critical values (Section 3) and then locating critical points within immediate basins (Section 4), including the Cantor-type and non-Cantor-type basins. The paper concludes with sharpness examples (Section 5) demonstrating that the bounds are tight in various regimes, thereby clarifying the landscape of attracting dynamics in the non-Archimedean setting and extending the analogies with Fatou–Julia theory in this context.
Abstract
In complex dynamics, a fundamental result of Fatou and Julia asserts that every attracting cycle of a rational map attracts a critical point. The analogous statement fails in non-Archimedean dynamics. For a non-Archimedean rational map, this paper establishes a sharp condition on the multiplier of an attracting cycle ensuring it attracts a critical point.
