|
Journal of Convex Analysis 28 (2021), No. 2, 495--508 Copyright Heldermann Verlag 2021 Weak Maximum Principle for Cooperative Systems: the Degenerate Elliptic Case Italo Capuzzo Dolcetta Dip. di Matematica, Università La Sapienza, Rome, Italy capuzzo@mat.uniroma1.it Antonio Vitolo Dip. di Ingegneria, Università di Salerno, Fisciano, Italy vitolo@unisa.it We consider cooperative systems of nonlinear degenerate elliptic equations. Conditions for the validity of the weak Maximum Principle are obtained through a reduction to a single scalar equation. A suitable index related to the principal eigenvalues of the Dirichlet problems for the operators involved in the system is introduced. The positivity of this index enforces the validity of the weak Maximum Principle. Keywords: Nonlinear elliptic systems, maximum principles, principal eigenvalues. MSC: 35J47, 35J70, 35B50, 35P30, 35D40. [ Fulltext-pdf (130 KB)] for subscribers only. |