Séminaire de Physique ThéoriqueInflationary Dynamics with Gauge-Fields
Kei-Ichi MAEDA (Waseda University, JAPAN)
Wednesday 24 October 2012 11:00 - Tours - Salle 1180 (Bât E2)
We study the dynamics of the universe with a scalar field and SU(2) non-Abelian gauge field . The scalar field has an exponential potential and the gauge field is coupled to the scalar field with an exponential function of the scalar field. We find that the magnetic components of the gauge field assists the expansion of the universe and a power-law inflation becomes possible even if the scalar field potential is steep. This power-law inflationary solution is a stable attractor in certain range of coupling parameters. Unlike the case with Abelian gauge multiplet fields, the power-law inflationary solution with the dominant electric components is unstable because of the existence of non-linear coupling of the gauge field. We also analyze the dynamics for the other parameter range, and find several attractor solutions.