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Related papers: 4d Simplicial Quantum Gravity: Matter Fields and t…

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We show that the phase transition previously observed in dynamical triangulation models of quantum gravity can be understood as being due to the creation of a singular link. The transition between singular and non-singular geometries as the…

High Energy Physics - Lattice · Physics 2009-10-30 S. Catterall , R. Renken , J. Kogut

This is an expanded and revised version of our geometrical analysis of the strong coupling phase of 4D simplicial quantum gravity. The main differences with respect to the former version is a full discussion of singular triangulations with…

High Energy Physics - Lattice · Physics 2009-10-31 J. Ambjorn , M. Carfora , D. Gabrielli , A. Marzuoli

Dynamical triangulations of four-dimensional Euclidean quantum gravity give rise to an interesting, numerically accessible model of quantum gravity. We give a simple introduction to the model and discuss two particularly important issues.…

High Energy Physics - Lattice · Physics 2008-11-26 B. Bruegmann , E. Marinari

A thorough numerical examination for the field theory of 4D quantum gravity (QG) with a special emphasis on the conformal mode dependence has been studied. More clearly than before, we obtain the string susceptibility exponent of the…

High Energy Physics - Lattice · Physics 2009-11-07 S. Horata , H. S. Egawa , T. Yukawa

We extend simulations of simplicial gravity in four dimensions to include {\it degenerate} triangulations and demonstrate that using this ensemble the geometric finite-size effects are much reduced. We provide strong numerical evidence for…

High Energy Physics - Lattice · Physics 2009-10-31 S. Bilke , G. Thorleifsson

We discuss scaling relations in four dimensional simplicial quantum gravity. Using numerical results obtained with a new algorithm called ``baby universe surgery'' we study the critical region of the theory. The position of the phase…

High Energy Physics - Theory · Physics 2009-07-09 Jan Ambjorn , Jerzy Jurkiewicz

We study four--dimensional simplicial gravity through numerical simulation with special attention to the existence of singular vertices, in the strong coupling phase, that are shared by abnormally large numbers of four--simplices. The…

High Energy Physics - Lattice · Physics 2009-10-28 T. Hotta , T. Izubuchi , J. Nishimura

We describe a method of Monte-Carlo simulations of simplicial quantum gravity coupled to matter fields. We concentrate mainly on the problem of implementing effectively the random, dynamical triangulation and building in a detailed-balance…

High Energy Physics - Lattice · Physics 2009-10-22 S. Bilke , Z. Burda , J. Jurkiewicz

Quantum gravity is investigated in the limit of a large number of space-time dimensions, using as an ultraviolet regularization the simplicial lattice path integral formulation. In the weak field limit the appropriate expansion parameter is…

High Energy Physics - Theory · Physics 2008-11-26 Herbert W. Hamber , Ruth M. Williams

Four-dimensional(4D) spacetime structures are investigated using the concept of the geodesic distance in the simplicial quantum gravity. On the analogy of the loop length distribution in 2D case, the scaling relations of the boundary volume…

High Energy Physics - Lattice · Physics 2009-10-28 H. S. Egawa , T. Hotta , T. Izubuchi , N. Tsuda , T. Yukawa

We investigate the weak-coupling limit, kappa going to infinity, of 3D simplicial gravity using Monte Carlo simulations and a Strong Coupling Expansion. With a suitable modification of the measure we observe a transition from a branched…

High Energy Physics - Lattice · Physics 2015-06-25 P. Bialas , B. Petersson , G. Thorleifsson

Our earlier renormalization group analysis of simplicial gravity is extended. A high statistics study of the volume and coupling constant dependence of the cumulants of the node distribution is carried out. It appears that the phase…

High Energy Physics - Lattice · Physics 2009-10-28 P. Bialas , Z. Burda , A. Krzywicki , B. Petersson

We analyze simplicial quantum gravity in four dimensions using the Regge approach. The existence of an entropy dominated phase with small negative curvature is investigated in detail. It turns out that observables of the system possess…

High Energy Physics - Lattice · Physics 2009-10-22 W. Beirl , E. Gerstenmayer , H. Markum , J. Riedler

We extend a model of four-dimensional simplicial quantum gravity to include degenerate triangulations in addition to combinatorial triangulations traditionally used. Relaxing the constraint that every 4-simplex is uniquely defined by a set…

High Energy Physics - Lattice · Physics 2009-10-31 S. Bilke , G. Thorleifsson

Two-dimensional random surfaces are studied numerically by the dynamical triangulation method. In order to generate various kinds of random surfaces, two higher derivative terms are added to the action. The phases of surfaces in the…

High Energy Physics - Lattice · Physics 2009-10-28 A. Fujitsu , N. Tsuda , T. Yukawa

We present a new Group Field Theory for 4d quantum gravity. It incorporates the constraints that give gravity from BF theory, and has quantum amplitudes with the explicit form of simplicial path integrals for 1st order gravity. The…

General Relativity and Quantum Cosmology · Physics 2014-11-18 Daniele Oriti

We performed detailed study of the phase transition region in Four Dimensional Simplicial Quantum Gravity, using the dynamical triangulation approach. The phase transition between the Gravity and Antigravity phases turned out to be…

High Energy Physics - Lattice · Physics 2009-10-22 M. E. Agishtein , A. A. Migdal

I discuss some results we have obtained recently in a lattice model for quantized gravity coupled to scalar matter in four dimensions. We have looked at how the continuous phase transition separating the smooth from the rough phase of…

High Energy Physics - Theory · Physics 2007-05-23 Herbert W. Hamber

I review recent progress in simplicial quantum gravity in three and four dimensions, in particular new results on the phase structure of modified models of dynamical triangulations, the application of a strong-coupling expansion, and the…

High Energy Physics - Lattice · Physics 2009-10-31 Gudmar Thorleifsson

We measure the fractal structure of four dimensional simplicial quantum gravity by identifying so-called baby universes. This allows an easy determination of the critical exponent $\g$ connected to the entropy of four-dimensional manifolds.

High Energy Physics - Theory · Physics 2009-10-22 J. Ambjorn , S. Jain , J. Jurkiewicz , C. F. Kristjansen