On roots of unity in orbits of rational functions
On roots of unity in orbits of rational functions
We consider a large class of univariate rational functions over a number field $\mathbb {K}$, including all polynomials over $\mathbb {K}$, and give a precise description of the exceptional set of such functions $h$ for which there are infinitely many initial points in the cyclotomic closure $\mathbb {K}^c$ for which …