Homoclinic and heteroclinic orbits in Lagrangian dynamical systems

Abstract

In this thesis, variational methods are used to study the existence of homoclinic and heteroclinic orbits in various contexts of Lagrangian dynamical systems: 1. Monotone twist maps, which can be presented as time-one maps of certain positive definite time-periodic Lagrangian systems whose configuration spaces are 1-dim tori. 2. Time-periodic Tonelli Lagrangian systems whose configuration spaces are finite dimensional closed (i.e., compact, boundaryless) and connected smooth Riemannian manifolds. 3. Time-independent Tonelli Lagrangian systems whose configuration spaces are a 2-dim tori.