A uniqueness result for some singular semilinear elliptic equations
  Given $\Omega$ a bounded open subset of $\mathbb{R}^N$, we consider nonnegative solutions to the singular semilinear elliptic equation $-\Delta\,u\,=\,\frac{f}{u^{\beta}}$ in $H^1_{loc}(\Omega)$, under zero Dirichlet boundary conditions. For $\beta>0$ and $f\in L^1(\Omega)$, we prove that the solution is unique. 
Annamaria Canino and Berardino Sciunzi
math.AP