Stability and the Equation of State for Kinky Vortons

Vortons are closed loops of superconducting strings carrying current and charge. A formalism has been developed to study vortons in terms of an elastic string approximation, but its implementation requires knowledge of the unknown equation of state, relating the string tension to the energy per unit length. Recently, a planar analogue of the vorton, known as a kinky vorton, has been introduced. In this paper we derive an exact formula for the equation of state of a kinky vorton and use it to calculate the properties of the associated elastic string, such as the transverse and longitudinal propagation speeds. In particular, the elastic string approximation predicts a complicated and highly non-trivial pattern of intervals of instability, which we are able to confirm using full field simulations. The implications of the results for vortons are also discussed.