Speaker
Description
The importance of the proper treatment of the wave function renormalization in the renormalization group analysis of quantum gravity is pointed out. The renormalization factor, sometimes called an inessential coupling, can be used to fix any one of the coupling constants, with the exception of the coupling constants that remain unchanged by the rescaling of the field. If we choose to fix the cosmological constant, the renormalization group equation tells us the flow of the Newton and $R^2$ couplings. We then find that the Newton coupling reaches a nontrivial ultraviolet fixed point and becomes small in the low energy, and the $R^2$ couplings are asymptotically free. For the asymptotically free fixed point of the higher curvature couplings, we find that both of the two independent terms are relevant operators in the high energy.
