Pointwise A Priori Estimates for Solutions to Some p-Laplacian Equations

In this paper, we apply blow-up analysis and Liouville type theorems to study pointwise a priori estimates for some quasilinear equations with p-Laplace operator. We first obtain pointwise interior estimates for the gradient of p-harmonic function, i.e., the solution of $Delta_{p}u=0, xinOmega$, which extends the well-established results of the interior estimates of the gradient of harmonic function. We then get singularity and decay estimates of the sign changing solution of Lane-Emden-Fowler type p-Laplace equation $-Delta_{p}u=|u|^{lambda-1}u, xinOmega$, which are then generalized for the equation with general right hand term $f(x,u)$, under some asymptotic conditions of $f$. Lastly, we get pointwise estimates for higher order derivatives of the solution of $-Delta u=u^{lambda},xinOmega$, the case of $p=2$ for p-Laplace equation.