Multicanonical simulation of 3D dynamical triangulation model and a new phase structure Original Research Article

We apply the multicanonical technique to the three-dimensional dynamical triangulation model, which is known to exhibit a first-order phase transition with the Einstein-Hilbert action. We first clarify the first-order nature of the phase transition with the Einstein-Hilbert action in several ways including a high-precision finite size scaling analysis. We then add a new local term to the action and confirm the conjecture made through the MCRG technique that the line of the first-order phase transition extends to the expanded phase diagram, ending at a point. The fractal dimension at the end point is measured to be around three up to the present size.