English

The critical height is a moduli height

Number Theory 2017-10-17 v3 Dynamical Systems

Abstract

The critical height of a rational function (with algebraic coefficients) is a natural measure of dynamical complexity, essentially an adelic analogue of the Lyapunov exponent. Coordinate-free, it is well-defined on moduli space, but bears no obvious relation to the arithmetic geometry of that space as a variety. At a conference in 2010, Silverman conjectured that this disconnect is superficial, and that in fact the critical height should be at least commensurate to any ample Weil height on the moduli space, except on the Lattes locus (where that has no hope of being true). Here, we prove that conjecture.

Keywords

Cite

@article{arxiv.1610.07904,
  title  = {The critical height is a moduli height},
  author = {Patrick Ingram},
  journal= {arXiv preprint arXiv:1610.07904},
  year   = {2017}
}

Comments

Fixed a great number of typos, and a few minor errors (with no impact on the results). Many thanks to the anonymous referees for their careful reading and useful comments

R2 v1 2026-06-22T16:31:07.937Z