## Elliptic curves as attractors in $${\mathbb P}^2$$. I: Dynamics.(English)Zbl 1136.37026

Summary: We study rational maps of the real or complex projective plane of degree two or more, concentrating on those that map a genus-one curve onto itself, necessarily by an expanding map. We describe relatively simple examples with a rich variety of interesting dynamical behaviors that are perhaps familiar to the applied dynamics community but not to specialists in several complex variables. For example, we describe smooth attractors with riddled or intermingled attracting basins, and we observe “blowout” bifurcations when the transverse Lyapunov exponent for the invariant curve changes sign. In the complex case, we prove that the genus-one curve (a topological torus) can never have a trapping neighborhood, yet it can have an attracting basin of large measure (perhaps even of full measure). We also describe examples in which there appear to be attracting Herman rings (topological cylinders mapped to themselves with irrational rotation number) with open attracting basin. Section 8 provides a more general discussion of Herman rings and Siegel disks for arbitrary holomorphic maps of $$\mathbb P^2(\mathbb C)$$, and the last section outlines open problems

### MSC:

 37F10 Dynamics of complex polynomials, rational maps, entire and meromorphic functions; Fatou and Julia sets 37C70 Attractors and repellers of smooth dynamical systems and their topological structure 37F45 Holomorphic families of dynamical systems; the Mandelbrot set; bifurcations (MSC2010) 37F50 Small divisors, rotation domains and linearization in holomorphic dynamics 14H52 Elliptic curves
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