A note on circle maps driven by strongly expanding endomorphisms on T

摘要

We investigate the dynamics of a class of smooth maps of the two-torus T~2 of the form T(x, y) = (Nx, f_x(y)), where f_x : T → T is a monotone family (in x) of orientation preserving circle diffeomorphisms and N ∈ Z_+ is large. For our class of maps, we show that the dynamics essentially is the same as that of the projective action of non-uniformly hyperbolic SL(2, R)-cocycles. This generalizes a result by L.S. Young [6] to maps T outside the (projective) matrix cocycle case.