Dynamics of low-degree rational inner skew-products on
Tom 128 / 2022
Streszczenie
We examine iteration of certain skew-products on the bidisk whose components are rational inner functions, with emphasis on simple maps of the form \Phi (z_1,z_2) = (\phi (z_1,z_2), z_2). If \phi has degree 1 in the first variable, the dynamics on each horizontal fiber can be described in terms of Möbius transformations but the global dynamics on the 2-torus exhibit some complexity, encoded in terms of certain \mathbb {T}^2-symmetric polynomials. We describe the dynamical behavior of such mappings \Phi and give criteria for different configurations of fixed point curves and rotation belts in terms of zeros of a related one-variable polynomial.