A unified approach to a class of strongly indefinite functionals
For a class of strongly indefinite functionals (i.e. functionals that are neither bounded from below or from above, even modulo subspaces of finite dimension or codimension) the authors prove some abstract results concerning the existence of a critical point. Applications of these abstract results to Hamiltonian systems, semilinear wave equations and noncooperative elliptic systems are presented.
scientific article; zbMATH DE number 877805