Positive solution Elliptic problem 3 Asymptotic behaviors 2 Asymptotic profiles 2 Eigenvalues and eigenfunctions 2 Existence of Solutions 2 Nonlinear eigenvalue problem 2 Principal eigenvalues 2 Quasilinear problems 2 Variational methods 2 linear and nonlinear eigenvalue problems 2 sub- and super-solutions 2 variational methods 2 Indefinite 1 Nonnegative solution 1 Singular elliptic problem 1 Sub-supersolution 1 Sublinear 1 Variational problems 1