P-adic interpolation of iterates

Abstract

Extending work of Bell and of Bell, Ghioca, and Tucker, we prove that for a p-adic analytic self-map f on a closed unit polydisk, if every coefficient of f(x)-x has valuation greater than that of p^{1/(p-1)}, then the iterates of f can be p-adically interpolated; i.e., there exists a function g(x,n) analytic in both x and n such that g(x,n) = f^n(x) whenever n is a nonnegative integer.