Revisiting Y junctions for strings with currents: Transonic elastic case

We studied the formation of Y junctions for transonic elastic strings. In particular, using the general solution for these strings, which is described by left- and right-moving modes, we obtained the dynamics of kinks and Y junctions. Considering the linearized ansatz for straight strings, we constructed the parameter region space for which the formation of Y junctions due to strings collisions is allowed.