Semiclassical Analysis of Spinfoam Model with a Small Barbero-Immirzi Parameter

21 pages, 2 figuresInternational audienceWe study the semiclassical behavior of Lorentzian Engle-Pereira-Rovelli-Livine (EPRL) spinfoam model, by taking into account of the sum over spins in the large spin regime. The large spin parameter \lambda and small Barbero-Immirzi parameter \gamma are treated as two independent parameters for the asymptotic expansion of spinfoam state-sum (such an idea was firstly pointed out in arXiv:1105.0216). Interestingly, there are two different spin regimes: