Existence of Classical Solutions for Nonlinear Elliptic Equations with Gradient Terms

Entropy (Basel). 2022 Dec 15;24(12):1829. doi: 10.3390/e24121829.

Abstract

This paper deals with the existence of solutions of the elliptic equation with nonlinear gradient term -Δu=f(x,u,∇u) on Ω restricted by the boundary condition u|∂Ω=0, where Ω is a bounded domain in RN with sufficiently smooth boundary ∂Ω, N≥2, and f:Ω¯×R×RN→R is continuous. The existence results of classical solutions and positive solutions are obtained under some inequality conditions on the nonlinearity f(x,ξ,η) when |(ξ,η)| is small or large enough.

Keywords: classical solution; elliptic equation; gradient term; positive solution.