title: Collisions of strings with Y junctions.
abstract: We study the dynamics of Nambu-Goto strings with junctions at which three strings meet. In particular, we exhibit one simple exact solution and examine the process of intercommuting of two straight strings in which they exchange partners but become joined by a third string. We show that there are important kinematical constraints on this process. The exchange cannot occur if the strings meet with very large relative velocity. This may have important implications for the evolution of cosmic superstring networks and non-Abelian string networks.
authors.affiliation: School of Physics and Astronomy, University of Nottingham, University Park, Nottingham NG7 2RD, United Kingdom. ed.copeland@nottingham.ac.uk
authors.forename: E J
authors.initials: EJ
authors.lastname: Copeland
authors.forename: T W B
authors.initials: TW
authors.lastname: Kibble
authors.forename: D A
authors.initials: DA
authors.lastname: Steer