Mode interactions with symmetry
This thesis deals with steady-state mode interaction problems with symmetry. We prove several results concerning problems invariant under the action of an arbitrary compact Lie group Γ. These include the existence of mixed-mode solutions and secondary Hopf bifurcations. We also consider the unfolding of the equations characterizing such problems. Where appropriate, we distinguish the case when Γ acts trivially on one of the modes. We then apply the results to the problems of the (1,3)-, (1,5)- and (1,3,5)-mode interactions with spherical symmetry. We also consider the (3,5)- and the (1,3,5)-mode interaction problems with SO(3) symmetry.