ar X iv : h ep - l at / 9 90 80 48 v 1 2 7 A ug 1 99 9 Phase Transition of 4 D Simplicial Quantum Gravity with U ( 1 ) gauge field

The phase transition of 4D simplicial quantum gravity coupled to U (1) gauge fields is studied using Monte-Carlo simulations. The phase transition of the dynamical triangulation model with vector field (NV = 1) is smooth as compared with the pure gravity(NV = 0). The node susceptibility (χ) is studied in the finite size scaling method. At the critical point, the node distribution has a sharp peak in contrast to the double peak in the pure gravity. From the numerical results, we expect that 4D simplicial quantum gravity with U (1) vector fields has higher order phase transition than 1st order, which means the possibility to take the continuum limit at the critical point.