%0 Journal Article %T A new characterization of Sobolev spaces on $\mathbb{R}^n$ %A Roc Alabern %A Joan Mateu %A Joan Verdera %J Mathematics %D 2010 %I arXiv %X In this paper we present a new characterization of Sobolev spaces on Euclidian spaces ($\mathbb{R}^n$). Our characterizing condition is obtained via a quadratic multiscale expression which exploits the particular symmetry properties of Euclidean space. An interesting feature of our condition is that depends only on the metric of $\mathbb{R}^n$ and the Lebesgue measure, so that one can define Sobolev spaces of any order of smoothness on any metric measure space. %U http://arxiv.org/abs/1011.0667v2