Existence of solutions to a Hamiltonian system without convexity condition on the nonlinearity.
Generic uniqueness of a minimal solution for variational problems on a torus.
Generic uniqueness of minimal configurations with rational rotation numbers in Aubry-Mather theory.
Homoclinic and periodic orbits for hamiltonian systems
Homoclinic orbits for a class of singular second order Hamiltonian systems in ℝ3
We consider a conservative second order Hamiltonian system in ℝ3 with a potential V having a global maximum at the origin and a line l ∩ 0 = ϑ as a set of singular points. Under a certain compactness condition on V at infinity and a strong force condition at singular points we study, by the use of variational methods and geometrical arguments, the existence of homoclinic solutions of the system.
Homoclinic orbits for a class of symmetric Hamiltonian systems.
Homoclinic solutions for a class of second order non-autonomous systems.
Homoclinic solutions for second-order non-autonomous Hamiltonian systems without global Ambrosetti-Rabinowitz conditions.
Homoclinic solutions of 2nth-order difference equations containing both advance and retardation
By using the critical point method, some new criteria are obtained for the existence and multiplicity of homoclinic solutions to a 2nth-order nonlinear difference equation. The proof is based on the Mountain Pass Lemma in combination with periodic approximations. Our results extend and improve some known ones.
Homoclinics : Poincaré-Melnikov type results via a variational approach
Hyperbolic characteristics on star-shaped hypersurfaces
Infinitely many homoclinic orbits for Hamiltonian systems with group symmetries.
Infinitely many periodic solutions for nonautonomous sublinear second-order Hamiltonian systems.
Involutions of real intervals
This paper shows a simple construction of continuous involutions of real intervals in terms of continuous even functions. We also study smooth involutions defined by symmetric equations. Finally, we review some applications, in particular a characterization of isochronous potentials by means of smooth involutions.
Length minimizing Hamiltonian paths for symplectically aspherical manifolds
In this note we consider the length minimizing properties of Hamiltonian paths generated by quasi-autonomous Hamiltonians on symplectically aspherical manifolds. Motivated by the work of Polterovich and Schwarz, we study the role, in the Floer complex of the generating Hamiltonian, of the global extrema which remain fixed as the time varies. Our main result determines a natural condition which implies that the corresponding path minimizes the positive Hofer length. We use this to prove that a quasi-autonomous Hamiltonian...
Maslov index for homoclinic orbits of hamiltonian systems
Module structure in Conley theory with some applications
A multiplicative structure in the cohomological version of Conley index is described following a joint paper by the author with K. Gęba and W. Uss. In the case of equivariant flows we apply a normalization procedure known from equivariant degree theory and we propose a new continuation invariant. The theory is applied then to obtain a mountain pass type theorem. Another illustrative application is a result on multiple bifurcations for some elliptic PDE.
Morse index and bifurcation of p-geodesics on semi Riemannian manifolds
Given a one-parameter family of semi Riemannian metrics on an n-dimensional manifold M, a family of time-dependent potentials and a family of trajectories connecting two points of the mechanical system defined by , we show that there are trajectories bifurcating from the trivial branch if the generalized Morse indices and are different. If the data are analytic we obtain estimates for the number of bifurcation points on the branch and, in particular, for the number of strictly conjugate...
Multibump solutions for an almost periodically forced singular Hamiltonian system.
Multichain-type solutions for Hamiltonian systems.