Iteration theory of noncommutative maps

Abstract

This note aims to study the iteration theory of noncommutative self-maps of bounded matrix convex domains. We prove a version of the Denjoy–Wolff theorem for the row ball and the maximal quantization of the unit ball of ${\mathbb{C}}^d$. For more general bounded matrix convex sets, we prove a version of Wolff’s theorem inspired by the results of Abate. Lastly, we use iteration and fixed point theory to generalize the commutative results of Davidson, Ramsey, and Shalit to quotients of the free semigroup algebra by WOT closed ideals.