Seminar

We can better understand and simulate many physical systems by developing simple models in which key physics is (hopefully) preserved.  A variational approach to deriving the simpler system provides insights into the underlying physics and preserves important symmetries and conserved quantities. An example of this in beam physics is the variational formulation of nonlinear particle beam interactions with electromagnetic waves. This formulation is employed to derive equations for free electron lasers where the usual static wiggler field is replaced by an electromagnetic wiggler. Another example of the utility of these ideas in describing collective dynamics is a three-wave model of laser-plasma interactions which incorporates temperature and nonlinear plasma wave frequency shifts. In this informal presentation, both older results and topics of ongoing research will be presented, including an example of the importance of nonlinear dynamics in designing experiments for antihydrogen research.