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SÉMINAIRE DU LERMA
OBSERVATOIRE DE PARIS
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Vendredi 2 avril 2004 à 14 h


77 avenue Denfert Rochereau, Paris 14



Salle de l'Atelier, Observatoire de Paris





Magnetic Fields in the early and in the present Universe



Massimo GIOVANNINI

(CERN, Theory Division)



Résumé : Heeding observations, there is plausible evidence for the existence of large-scale magnetic fields in galaxies and in clusters of galaxies. Furthermore, if magnetic fields are present prior to the decoupling of radiation from matter, various known phenomena may be affected such as the electroweak phase transition, the synthesis of the light isotopes and the polarization of the Cosmic Microwave Background. I will discuss the present evidence and the early implications large-scale magnetization. I will also analyze the problem of the origin of magnetic fields in light of our present understanding of cosmology and high-energy physics.