Speaker
Description
Cosmic strings arise naturally in theories with spontaneously broken symmetries and can carry important information about the dynamics of phase transitions in the early Universe. In this talk I will present a systematic framework for deriving the effective action governing the Goldstone degrees of freedom associated with the breaking of spacetime symmetries by string defects, together with their couplings to massive bound states localized on the string. I will show how the predictions of the resulting worldsheet effective theory compare with the full field-theoretic evolution of local strings, highlighting situations in which massive excitations can significantly affect the string dynamics. Finally, I will discuss possible implications for cosmic string network evolution and the resulting gravitational wave spectrum.