Critical point theory for asymptotically quadratic functionals and applications to problems with resonance

Abstract critical point theorems and applications to some nonlinear problems with “strong” resonance at infinity

Paolo Bartolo, Vieri Benci, Donato Fortunato · Nonlinear Analysis · 1983 · 791 citations

Natural Sciences, Mathematics, Differential Equations +14

Morse‐type index theory for flows and periodic solutions for Hamiltonian Equations

Charles C. Conley, Eduard Zehnder · Communications on Pure and Applied Mathematics · 1984 · 466 citations

Natural Sciences, Mathematics, Differential Equations +13

Nontrivial solutions for a class of nonresonance problems and applications to nonlinear differential equations

Herbert Amann, Edward J. Zehnder · French digital mathematics library (Numdam) · 1980 · 314 citations

Natural Sciences, Mathematics, Computational Electromagnetics +13

On differentiable functions with isolated critical points

Detlef Gromoll, Wolfgang Meyer · Topology · 1969 · 277 citations

Natural Sciences, Emergency Medical Services, Differential Equations +8

Solutions of asymptotically linear operator equations via morse theory

Kung Ching Chang · Communications on Pure and Applied Mathematics · 1981 · 196 citations

Natural Sciences, Mathematics, Differential Equations +12