H.S. Egawa

Scaling Behavior in 4D Simplicial Quantum Gravity

Scaling relations in four-dimensional simplicial quantum gravity are proposed using the concept of the geodesic distance. Based on the analogy of a loop length distribution in the two-dimensional case, the scaling relations of the boundary volume distribution in four dimensions are discussed in three regions: the strong-coupling phase, the critical point and the weak-coupling phase. In each phase different scaling behavior is found.Scaling relations in four-dimensional simplicial quantum gravity are proposed using the concept of the geodesic distance. Based on the analogy of a loop length distribution in the two-dimensional case, the scaling relations of the boundary volume distribution in four dimensions are discussed in three regions: the strong-coupling phase, the critical point and the weak-coupling phase. In each phase a different scaling behavior is found.

Phase Structure of Four-Dimensional Simplicial Quantum Gravity with a U(1) Gauge Field

The phase structure of four-dimensional simplicial quantum gravity coupled to U(1) gauge fields has been studied using Monte-Carlo simulations. The smooth phase is found in the intermediate region between the crumpled phase and the branched polymer phase. This new phase has a negative string susceptibility exponent, even if the number of vector fields (Nv) is 1. The phase transition between the crumpled phase and the smooth phase has been studied by a finite size scaling method. From the numerical results, we expect that this model (coupled to one gauge field) has a higher order phase transition than first order, which means the possibility to take the continuum limit at the critical point. Furthermore, we consider a modification of the balls-in-boxes model for a clear understanding of the relation between the numerical results and the analytical one.The phase structure of four-dimensional simplicial quantum gravity coupled to a U(1) gauge field is investigated numerically with the dynamical triangulation method. A smooth phase is found in the region between the crumpled phase and the branched polymer phase. This new phase has a negative string susceptibility exponent. The phase transition between the smooth phase and the crumpled phase is studied using the finite size scaling method. From the numerical results we conclude that this model has a phase transition that is higher than first-order. Numerical results suggest a possibility of the existence of the continuum limit at the critical point.

Matter Dependence of the String Susceptibility Exponent in Four-Dimensional Simplicial Quantum Gravity

The dependence of the number of vector and scalar fields on the string susceptibility exponent is evaluated numerically for four-dimensional simplicial quantum gravity using the grand canonical ensemble method. The numerical result indicates that the four-dimensional simplicial quantum gravity reproduces well predictions of the four-dimensional conformal gravity.

Numerical analysis of the double scaling limit in the bosonic part of the II-B matrix model☆

The bosonic IIB matrix model is studied using a numerical method. This model contains the bosonic part of the IIB matrix model conjectured to be a non-perturbative definition of the type IIB superstring theory. The large N scaling behavior of the model is shown performing a Monte Carlo simulation. The expectation value of the Wilson loop operator is measured and the string tension is estimated. The numerical results show the prescription of the double scaling limit.Abstract The bosonic IIB matrix model, which contains the bosonic part of the IIB matrix model conjectured to be a non-perturbative definition of the type IIB superstring theory, is studied using a numerical method. The large N scaling behavior of the model is shown performing a Monte Carlo simulation. The expectation value of the Wilson loop operator is measured and the string tension is estimated. From the numerical results, the prescription of the double scaling limit is obtained.

Phase transition of 4D 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 (

A consideration of information content on the basis of semiotics taking account of virtual reality

N_{V}=1

Scaling structures in four-dimensional simplicial gravity☆

) is smooth as compared with the pure gravity(

Grand-canonical simulation of 4D simplicial quantum gravity

N_{V}=0

Common structures in simplicial quantum gravity

). The node susceptibility (

Clear evidence of a continuum theory of 4D Euclidean simplicial quantum gravity

\chi