A Criterion for Potentially Good Reduction in Non-archimedean Dynamics
arXiv:1311.6695
Abstract
Let K be a non-archimedean field, and let f in K(z) be a polynomial or rational function of degree at least 2. We present a necessary and sufficient condition, involving only the fixed points of f and their preimages, that determines whether or not the dynamical system f on P^1 has potentially good reduction.
7 pages; typos corrected and a little extra commentary added