2026/07/29 by Daniele Galli, Eleonora Passaglia, Andrea Ulliana
Mathematics · #math.DS #math.FA #msc:28A78 #msc:28A80 #msc:37C40 #msc:37C70 #msc:37D20
22 pages
arxiv created 2026/07/29 · arxiv updated 2026/07/30
We study the skew product systems T: \mathbbS1×ℝd → \mathbbS1 ×ℝd, T(x,y)=(ℓ x, A y+ϕ(x)), where ℓ≥ 2, A ∈ GLd(ℝ) with ρ(A)<1, and ϕ∈ Cr(\mathbbS1, ℝd). We allow the fibers to have any dimension and A to be non-conformal. We show that: when |det(A)|ℓ<1, for almost every ϕ, the Hausdorff dimension of the solenoid attractor and the SRB measure equals the affinity dimension; when |det(A)|ℓ>1, for almost every ϕ, the SRB measure is absolutely continuous. We introduce a derivative dispersion condition, replacing the usual transversality condition.