Attractive interaction between pulses in a model for convection in binary mixtures

Recent experiments on convection in binary mixtures have shown that the interaction between localized waves (pulses) can be repulsive as well as attractive and depends strongly on the relative orientation of the pulses. It is demonstrated that the concentration mode, which is characteristic of the extended Ginzburg-Landau equations introduced recently, allows a natural understanding of that result. Within the standard complex Ginzburg-Landau equation this would not be possible.