Y-junction intercommutations of current carrying strings
  Under certain conditions the collision and intercommutation of two cosmic
strings can result in the formation of a third string, with the three strings
then remaining connected at Y-junctions. The kinematics and dynamics of
collisions of this type have been the subject of analytical and numerical
analyses in the special case in which the strings are Nambu-Goto. Cosmic
strings, however, may well carry currents, in which case their dynamics is not
given by the Nambu-Goto action. Our aim is to extend the kinematic analysis to
more general kinds of string model. We focus in particular on the collision of
strings described by conservative elastic string models, characteristic of
current carrying strings, and which are expected to form in a cosmological
context. As opposed to Nambu-Goto strings collisions, we show that in this case
the collision cannot lead to the formation of a third elastic string: if
dynamically such a string forms then the joining string must be described by a
more general equation of state. This process will be studied numerically in a
forthcoming publication.
