Wobbling kinks and shape mode interactions in a coupled two-component [formula omitted] theory.

The dynamics of a wobbling kink in a two-component coupled ϕ 4 scalar field theory (with an excited orthogonal shape mode) is addressed. For this purpose, the vibration spectrum of the second order small kink fluctuation is studied in order to find the corresponding vibration modes associated to the first (longitudinal) and second (orthogonal) field components. By means of this analysis, it was found that the number of possible shape modes depends on the value of the coupling constant. It is notable that when one of the orthogonal field shape modes is initially triggered, the unique shape mode of the longitudinal field is also activated. This coupling causes the kink to emit radiation with twice the frequency of excited mode in the first field component. Meanwhile, in the orthogonal channel we find radiation with two different frequencies: one is three times the frequency of the orthogonal wobbling mode and another is the sum of the frequencies of the longitudinal shape mode and the triggered mode. All the analytical results obtained in this study have been successfully contrasted with those obtained through numerical simulations. • The dynamics of a wobbler in a two component field theory is studied. • The number of shape modes is shown to depend on the value of the coupling constant. • When one orthogonal mode is triggered, the mode of the first field is activated. • The kink emits radiation with twice the frequency of the excited mode in the first component. • In the orthogonal channel radiation with two different frequencies appear. [ABSTRACT FROM AUTHOR]