A characterization of the eigenvalues of a completely continuous selfadjoint operator
A critical point result for non-differentiable indefinite functionals
In this paper, two deformation lemmas concerning a family of indefinite, non necessarily continuously differentiable functionals are proved. A critical point theorem, which extends the classical result of Benci-Rabinowitz [14, Theorem 5.29] to the above-mentioned setting, is then deduced.
A double eigenvalue problem for Schrödinger equations involving sublinear nonlinearities at infinity.
A few symmetry results for nonlinear elliptic PDE on noncompact manifolds
A framework for Morse theory for the Yang-Mills functional.
A free boundary problem involving limiting Sobolev exponents.
A general mountain pass principle for locating and classifying critical points
A generalization of Ekeland's variational principle with applications.
A Morse index for geodesics in static Lorentz manifolds.
A Morse lemma at infinity for Yamabe type problems on domains
A Morse lemma for degenerate critical points with low differentiability.
A Morse theory for annulus-type minimal surfaces.
A mountain pass theorem for actions of compact Lie groups.
A new obstruction to embedding Lagrangian tori.
A nonexistence result for Yamabe type problems on thin annuli
A nonlinear second order problem with a nonlocal boundary condition.
A Note on Coercivity of Lower Semicontinuous Functions and Nonsmooth Critical Point Theory
The first motivation for this note is to obtain a general version of the following result: let E be a Banach space and f : E → R be a differentiable function, bounded below and satisfying the Palais-Smale condition; then, f is coercive, i.e., f(x) goes to infinity as ||x|| goes to infinity. In recent years, many variants and extensions of this result appeared, see [3], [5], [6], [9], [14], [18], [19] and the references therein. A general result of this type was given in [3, Theorem 5.1] for a lower...
A note on quasilinear elliptic eigenvalue problems.
A note on strong resonance problems for -Laplacian.
A note on the existence of two nontrivial solutions of a resonance problem.