2022/02/14 by Bera, Sayani
#32H50 #37F80 #Complex Variables (math.CV) #Dynamical Systems (math.DS) #FOS: Mathematics
paper · doi:10.48550/arxiv.2202.06522
The goal of this article is two fold. Firstly, we explore the dynamics of a semigroup of polynomial automorphisms of ℂ2, generated by a finite collection of Hénon maps. In particular, we construct the positive and negative dynamical Green's functions G_\mathscrG^± and the corresponding dynamical Green's currents μ_\mathscrG^± for a semigroup S, generated by a collection \mathscrG. Using them, we show that the positive (or negative) Julia set of the semigroup S, i.e., JS+ (or JS-) is equal to the closure of the union of individual positive (or negative) Julia sets of the maps, in the semigroup S. Furthermore, we prove that μ_\mathscrG+ is supported on the whole of JS+ and is also the unique positive closed (1,1)-current supported on JS+, satisfying a semi-invariance relation that depends on the generating set \mathscrG. Secondly, we study the dynamics of a non-autonomous sequence of Hénon maps, say \hk\, contained in the semigroup S. Similarly, as above, here too, we construct the non-autonomous dynamical positive and negative Green's function and the corresponding dynamical Green's currents. Further, we use the properties of Green's function to conclude that the non-autonomous attracting basin of any such sequence \hk\, sharing a common attracting fixed point, is biholomorphic to ℂ2.