Abstract and Applied Analysis
Volume 2008 (2008), Article ID 178534, 19 pages
doi:10.1155/2008/178534

Harnack inequalities and ABP estimates for nonlinear second-order elliptic equations in unbounded domains

M.E. Amendola1 , L. Rossi2 and A. Vitolo1

1Dipartimento di Matematica e Informatica, Università di Salerno, P. Grahamstown, 84084 Fisciano (SA), Italy
2Dipartimento di Matematica, Università di Roma “La Sapienza”, P. le A. Moro 2, 00185 Roma, Italy

Abstract

We are concerned with fully nonlinear uniformly elliptic operators with a superlinear gradient term. We look for local estimates, such as weak Harnack inequality and local maximum principle, and their extension up to the boundary. As applications, we deduce ABP-type estimates and weak maximum principles in general unbounded domains, a strong maximum principle, and a Liouville-type theorem.