Uniform parameterization of subanalytic sets and diophantine applications

Abstract

We prove new parameterization theorems for sets definable in the structure ${\mathbb{R}}_{an}$ (i.e. for globally subanalytic sets) which are uniform for definable families of such sets. We treat both $C^r$-parameterization and (mild) analytic parameterization. In the former case we establish a polynomial (in $r$) bound (depending only on the given family) for the number of parameterizing functions. However, since uniformity is impossible in the latter case (as was shown by Yomdin via a very simple family of algebraic sets), we introduce a new notion, analytic quasi-parameterization (where many-valued complex analytic functions are used), which allows us to recover a uniform result. We then give some diophantine applications motivated by the question as to whether the $H^{o(1)}$ bound in the Pila-Wilkie counting theorem can be improved, at least for certain reducts of ${\mathbb{R}}_{an}$. Both parameterization results are shown to give uniform $(\log H{)}^{O(1)}$ bounds for the number of rational points of height at most $H$ on ${\mathbb{R}}_{an}$-definable Pfaffian surfaces. The quasi-parameterization technique produces the sharper result, but the uniform $C^r$-parametrization theorem has the advantage of also applying to ${\mathbb{R}}_{an}^{pow}$-definable families.