Quasilinear elliptic equations with singular quadratic growth terms

In this paper we deal with positive solutions for singular quasilinear problems whose model is \begin{cases} -Δu + \frac{|\nabla u|^2}{(1-u)^γ}=g & in $Ω$,\newline \hfill u=0 \hfill & on $\partialΩ$, \end{cases} where $\mathrm{\Omega }$ is a bounded open set of ${\mathbb{R}}^N$, $g\ge 0$ is a function in some Lebesgue space, and $\gamma >0$. We prove both existence and nonexistence of solutions depending on the value of $\gamma$ and on the size of $g$.