Lower bounds for blow-up time in a nonlinear parabolic problem with a gradient nonlinearity

In this article, we study the blow-up properties of solutions to a parabolic problem with a gradient nonlinearity under homogeneous Dirichlet boundary conditions. By constructing an auxiliary function and by modifying the first order differential inequality, we obtain lower bounds for the blow-up time of solutions in L-k (Omega) (k > 1) norm and conditions which ensure that blow-up cannot occur.