{ "id": "1905.08344", "version": "v1", "published": "2019-05-20T20:51:21.000Z", "updated": "2019-05-20T20:51:21.000Z", "title": "Regularity of the Density of SRB Measures for Solenoidal Attractors", "authors": [ "Carlos Bocker", "Ricardo Bortolotti" ], "categories": [ "math.DS" ], "abstract": "We show that a class of higher-dimensional hyperbolic endomorphisms admit absolutely continuous invariant probabilities whose density are regular. The maps we consider are given by $T(x,y) = (E (x), C(y) + f(x) )$, where $E$ is a linear expanding map of $\\mathbb{T}$, $C$ is a linear contracting map of $\\mathbb{R}^d$, $f$ is in $C^r(\\mathbb{T}^u,\\mathbb{R}^d)$ and $r \\geq 2$. We prove that if $|(\\det C)(\\det E)| \\|C^{-1}\\|^{-2s}>1$ for some $s\\frac{u+d}{2}$ then the density is $C^k$ for every $k