Integrality properties of Böttcher coordinates for one-dimensional superattracting germs

Adriana Salerno, Joseph H. Silverman

Let $R$ be a ring of characteristic $0$ with field of fractions $K$, and let $m\ge 2$. The Böttcher coordinate of a power series $\phi (x)\in x^m+x^{m+1}R[[x]]$ is the unique powe…