#### August 30, 10:15 in A315

#### Shahin Sheikh-Jabbari (IPM,
Tehran)

#### Gauge-flation: Inflation from Non-Abelian Gauge Fields

Abstract: We introduce an inflationary scenario, Non-Abelian Gauge Field
Inflation or gauge-flation for short, in which slow-roll inflation is
driven by non-Abelian gauge field minimally coupled to gravity. I present
a detailed analysis, both numerical and analytical, of the gauge-flation.
By studying the phase diagrams of the theory, we show that getting enough
number of e-folds during a slow-roll inflation is fairly robust to the
choice of initial gauge field values. In addition, I show the results of
the gauge-flation cosmic perturbation theory which has its own specific
features and novelties. The specific gauge-flation model I analyze in this
talk has two parameters, a cutoff scale Lambda and the gauge coupling g.
Fitting our results with the current cosmological data fixes Lambda ~ 10 H
~ 10^{15} GeV (H is the Hubble parameter) and g ~ 10^{-4}, which are in
the natural range of parameters in generic particle physics beyond
standard models. Our model also predicts a tensor-to-scalar ratio r>0.05,
in the range detectable by the Planck satellite.