English

Examples of dynamical degree equals arithmetic degree

Number Theory 2012-12-14 v1 Dynamical Systems

Abstract

Let f : X --> X be a dominant rational map of a projective variety defined over a number field. An important geometric-dynamical invariant of f is its (first) dynamical degree d_f= lim SpecRadius((f^n)^*)^{1/n}. For algebraic points P of X whose forward orbits are well-defined, there is an analogous (upper) arithmetic degree a_f(P) = limsup h_X(f^n(P))^{1/n}, where h_X is an ample Weil height on X. In an earlier paper, we proved the fundamental inequality a_f(P) \le d_f and conjectured that a_f(P) = d_f whenever the orbit of P is Zariski dense. In this paper we show that the conjecture is true for several types of maps. In other cases, we provide support for the conjecture by proving that there is a Zariski dense set of points with disjoint orbits and satisfying a_f(P) = d_f.

Keywords

Cite

@article{arxiv.1212.3015,
  title  = {Examples of dynamical degree equals arithmetic degree},
  author = {Shu Kawaguchi and Joseph H. Silverman},
  journal= {arXiv preprint arXiv:1212.3015},
  year   = {2012}
}

Comments

25 pages

R2 v1 2026-06-21T22:53:39.819Z