Cosmic and superconducting strings
Prof. Betti Hartmann (University of Sao Paulo)

Topological defects (aka topological solitons) appear in field theory models with spontaneous symmetry breaking and a non-trivial vacuum manifold. Cosmic strings are created whenever a U(1) symmetry gets spontaneously broken and are the topological defect that seems most important from the point of view of cosmological applications. There are several reasons for this: on the one hand it is believed that cosmic strings might be linked to the fundamental strings of String theory and on the other essentially all models that try to embed the Theory of Inflation into the scheme of Grand Unification predict the production of cosmic strings. Furthermore, the analysis of recent Cosmic Microwave Background (CMB) data suggests that cosmological models containing cosmic strings provide a viable fit to both the temperature as well as polarization anisotropy spectra. I will discuss the “zoo” of cosmic strings available and also comment on so-called superconducting strings which can have an additional internal structure in the form of bosonic or fermionic fields.