CP3 Lunch - Coupled currents in cosmic strings - Marc Lilley

by Dr Marc Lilley (UCL - CP3)

Wednesday 7 Apr 2010, 13:00 → 13:50 Europe/Brussels

Seminar room (E.349)

After an introduction to the single current carrying cosmic string from the field theory side and in Carter's macroscopic description, I will show how both formalisms can be simply extended to a string carrying more than one current. I will then discuss the conditions for stability of the string if transverse and/or longitudinal perturbations of the currents are included. I will also give numerical examples to show that, in the weak coupling limit, the physics of a string carrying several currents is well reproduced by an analytic model in which the worldsheet Lagrangian of each string is approximated by, on the one hand, a logarithmic function of two parameters for timelike currents, and by, on the other hand, a rational function of two parameters for spacelike currents.