Non-Abelian gauge field inflation

In [A. Maleknejad and M. M. Sheikh-Jabbari, arXiv:1102.1513.] we introduced 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. We present a more 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, we present a detailed analysis of the cosmic perturbation theory in gauge-flation which has many special and interesting features compared the standard scalar-driven inflationary models. The specific gauge-flation model we study in this paper has two parameters, a cutoff scale Lambda and the gauge coupling g. Fitting our results with the current cosmological data fixes Lambda similar to 10H similar to 10(15) GeV (H is the Hubble parameter) and g similar to 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.