Phase transitions in the core of global embedded defects

We demonstrate the existence of global monopole and string configurations whose care exhibits a phase structure. We determine the critical values of parameters for which the transition from the symmetric to the non-symmetric phase occurs and discuss the dynamics implied by the non-symmetric cores for defect interactions. These effects are relevant and experimentally observable for condensed matter systems such as liquid crystals and He-3. We model phase transitions in the core of global embedded topological defects by identifying the relevant parameters with the vacuum expectation value of a dynamical scalar field. Finally, we argue that superheavy defects that undergo a core phase transition in the very early universe provide a novel realization for topological inflation. [S0556-2821(98)06818-0].