General estimate for the graviton lifetime

By means of general kinematical arguments, the lifetime τ of a graviton of energy E for decay into gravitons is found to have the form τ−1(1/EG)Σj=1,2,… cj(ΛG)j. Some recent, preliminary results of non perturbative simplicial quantum gravity are then employed to estimate the effective values of G and AG. It turns out that a short lifetime of the graviton cannot be excluded.