arXiv subjects
Publications and source records attributed to Akseli Haarala.
We prove a global version of the classical result that $p$-harmonic functions belong to $W^{2,2}_{loc}$ for $1<p<3+\frac{2}{n-2}$. The proof relies on Cordes' matrix inequalities [7] and techniques from the work of Cianchi and Maz'ya [5,6].
We study the minimizer of the electrostatic Born--Infeld energy \begin{equation*} \int_{\mathbb{R}^n}1-\sqrt{1-|D v|^2}\ dx-\int_{\mathbb{R}^n}ρv\ dx, \end{equation*} which vanishes at infinity. We show that the minimizer $u$ is strictly spacelike and it is a weak solution to \begin{equation*}-\operatorname{div}\Big(\frac{D u}{\sqrt{1-|D u|^2}}\Big)=ρ,\end{equation*} provided that $ρ$ is in the dual space of the solution space and $ρ\in L^p(\mathbb{R}^n)$, for some $p>n\geq 3$. Moreover, we have $u\in C^{1,α}(\mathbb{R}^n)$ for some $α\in (0,1)$.