Boundary behavior in the Loewner-Nirenberg problem

Abstract

Let $\Omega\subset\mathbb R^n$ be a bounded domain of class $C^{2+\alpha}$, $0<\alpha<1$. We show that if $n\geq 3$ and $u_\Omega$ is the maximal solution of equation $\Delta u = n(n-2)u^{(n+2)/(n-2)}$ in $\Omega$, then the hyperbolic radius $v_\Omega=u_\Omega^{-2/(n-2)}$ is of class $C^{2+\alpha}$ up to the boundary. The argument rests on a reduction to a nonlinear Fuchsian elliptic PDE.