Speaker
Description
Infrared divergence is a common feature of spinfoam models with a vanishing cosmological constant. The disappearance of divergence at the present of a non-zero cosmological constant was conjectured and then recently proved in a spinfoam model constructed with complex Chern-Simons theory. Based on this spinfoam model, we study how such divergence depends on the value of the cosmological constant. In this talk, I will present our recent results on the first-order divergence, also called the radiative correction, of the 4D spinfoam model with a cosmological constant. Taking the cosmological constant to approach the zero limit, our analysis gives a lower bound on the divergence, which is an inverse power law in (the absolute value of) the cosmological constant.
