Dynamics of a string coupled to gravitational waves II - Perturbations propagate along an infinite Nambu-Goto string

摘要

The perturbative modes propagating along an infinite string are investigatedwithin the framework of the gauge invariant perturbation formalism on aspacetime containing a self-gravitating straight string with a finitethickness. These modes are not included in our previous analysis. Wereconstruct the perturbation formalism to discuss these modes and solve thelinearized Einstein equation within the first order with respect to the stringoscillation amplitude. In the thin string case, we show that the oscillationsof an infinite string must involve the propagation of cosmic string travelingwave.