Résumé / Abstract Seminaire_GReCO

"Bosonic structure of F-term supersymmetric cosmic strings in a realistic GUT context"

E. Allys

Cosmic strings, i.e. linear topological defects which are expected to form during the Spontaneous Symmetry Breaking (SSB) of a Grand Unified Theory (GUT), permit to probe particle physics up to energies around 10^16 GeV: the lack of observational signatures provide serious constraints for those theories. Until now, only toy-models have been used to describe strings, assuming a minimal field content necessary to form them. However, an actual implementation of their microscopic structure in a realistic particle physic and cosmological context could give new insights. For example, the property to have the scale of formation of the strings as only characteristic energy can be wrong, due to possible contributions of higher energy fields. Moreover, such a study would permit to obtain the energy per unit length of the strings as a function of the GUT parameters.

We will present the results of such realistic studies, both in a very general GUT theory, and in a given SO(10) model, assuming standard hybrid inflation. In both cases, we will see how the cosmological and particle physics aspects of the model permit to reduce the string study to the dynamics of only a few fields. Giving an ansatz for these realistic structures, we will present the numerical solutions of the model, and discuss the different properties of the strings as a function of the GUT parameters. We will also discuss how to evaluate in a perturbative way the modifications of the energy per unit length from standard toy model values, and discuss the agreement with the numerical solutions. It will permit to distinguish two classes of strings, with very different properties.

lundi 9 novembre 2015 - 11:00
Salle des séminaires Évry Schatzman,
Institut d'Astrophysique de Paris

Page web du séminaire / Seminar's webpage