Approximation of non-archimedean Lyapunov exponents and applications over global fields
Abstract
Let be an algebraically closed field of characteristic 0 that is complete with respect to a non-archimedean absolute value. We establish a locally uniform approximation formula of the Lyapunov exponent of a rational map of of degree over , in terms of the multipliers of -periodic points of , with an explicit control in terms of , and . As an immediate consequence, we obtain an estimate for the blow-up of the Lyapunov exponent near a pole in one-dimensional families of rational maps over . Combined with our former archimedean version, this non-archimedean quantitative approximation allows us to show: - a quantified version of Silverman's and Ingram's recent comparison between the critical height and any ample height on the moduli space , - two improvements of McMullen's finiteness of the multiplier maps: reduction to multipliers of cycles of exact given period and an effective bound from below on the period, - a characterization of non-affine isotrivial rational maps defined over the function field of a normal projective variety in terms of the growth of the degree of the multipliers.
Cite
@article{arxiv.1803.06859,
title = {Approximation of non-archimedean Lyapunov exponents and applications over global fields},
author = {Thomas Gauthier and Yusuke Okuyama and Gabriel Vigny},
journal= {arXiv preprint arXiv:1803.06859},
year = {2018}
}
Comments
Some typos fixed