A modified sine-Gordon theory with static multi-kinks

We construct a modified non-BPS sine-Gordon theory which supports stable static kinks of arbitrary topological degree $N$. We use this toy model to study problems which are interesting for higher-dimensional soliton theories supporting multi-solitons. We construct a 2-kink collective coordinate model and use it to generate scattering trajectories, which are compared to full-field dynamics. We find that the approximation works well, but starts to fail as radiation becomes more important due to our model becoming less BPS or when the initial kink velocities are large. We also construct the quantum 2-kink and calculate one-loop corrections to the 1- and 2-kinks. We consider how these quantum corrections affect the binding energy of the 2-kink.