Diffeomorphisms with stable manifolds as basin boundary

In this paper we study the dynamics of a family of diffeomorphisms in $\bR^2$ defined by $F(x,y)=(g(x)+h(y),h(x)),$ where $g(x)$ is a unimodal $C^2$-map which has the same dynamical properties as the logistic map $P(x)=\mu x(1-x)$, and $h(x)$ is a $C^2$ map which is a small perturbation of a linear map. For certain maps of this form we show that there are exactly two periodic points, namely an attracting fixed point and a saddle fixed point and the boundary of the basin of attraction is the stable manifold of the saddle. The basin boundary also has the same regularity as $F$, in contrast to the frequently observed fractal nature of basin boundaries. To establish these results we describe the orbits under forward and backward iteration of every point in the plane.