preprint

Inserted: 8 mar 2022
Last Updated: 25 may 2023

Year: 2022

Abstract:

We discuss Meyers-Serrin's type results for smooth approximations of functions $b=b(t,x):\mathbb{R}\times\mathbb{R}^n\to\mathbb{R}^m$, with convergence of an energy of the form \[ \int_{\mathbb{R}}\int_{\mathbb{R}^n} w(t,x) \varphi\left(
Db(t,x)
\right)\mathrm{d} x \mathrm{d} t\,, \] where $w>0$ is a suitable weight function, and $\varphi:[0,\infty)\to [0,\infty)$ is a convex function with $\varphi(0)=0$ having exponential or sub-exponential growth.