The precise boundary trace of solutions of a class of supercritical   nonlinear equations
  We construct and study the properties of the precise boundary trace of positive solutions of $-\Delta u+u^q=0$ in a smooth bounded domain of $\mathbb R^N$, in the supercritical case $q\geq q_c=(N+1)/(N-1)$ 
Moshe Marcus, Laurent Veron (LMPT)