Pseudo-orbits of Contact Forms (Pitman Research Notes in Mathematics)

(This books presents a variational problem in geometry and dynamical systems lacking compactness. This lack of compactness is shown to be intrinsically related to the variational problem, via the failure of the Palais-Smale condition. A new concept is then introduced, in this framework: critical points at infinity. These are then precisely studied in this framework to show that they arise naturally in many problems ranging from partial differential equations to geometry and dynamical systems.
In a further volume in The Research Notes in Mathematics series Critical points at infinity in some variational problems:, the author develops his ideas further. Both books will be of interest to applied, in addition to pure, mathematicians.)