Uniqueness and boundary behavior of large solutions to elliptic problems with singular weights

We consider the elliptic problems Deltau = a(x)u(m), m > 1, and Deltau = a(x)e(u) in a smooth bounded domain Omega, with the boundary condition u = +infinity on partial derivativeOmega. The weight function a(x) is assumed to be Holder continuous, growing like a negative power of d(x) = dist(x, partial derivativeOmega) near partial derivativeOmega. We show existence and nonexistence results, uniqueness and asymptotic estimates near the boundary for both the solutions and their normal derivatives.