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Related papers: Fractal Dimension in 3d Spin-Foams

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We show that the spectral dimension d_s of two-dimensional quantum gravity coupled to Gaussian fields is two for all values of the central charge c <= 1. The same arguments provide a simple proof of the known result d_s= 4/3 for branched…

High Energy Physics - Theory · Physics 2010-02-03 J. Ambjorn , D. Boulatov , J. L. Nielsen , J. Rolf , Y. Watabiki

Within the causal dynamical triangulations approach to the quantization of gravity, striking evidence has emerged for the dynamical reduction of spacetime dimension on sufficiently small scales. Specifically, the spectral dimension…

General Relativity and Quantum Cosmology · Physics 2019-07-31 Joshua H. Cooperman , Manuchehr Dorghabekov

We study phases and fractal structures of three-dimensional simplicial quantum gravity by the Monte-Carlo method. After measuring the surface area distribution (SAD) which is the three-dimensional analog of the loop length distribution…

High Energy Physics - Lattice · Physics 2009-10-28 Hiroyuki Hagura , Noritsugu Tsuda , Tetsuyuki Yukawa

We measure the spectral dimension of universes emerging from nonperturbative quantum gravity, defined through state sums of causal triangulated geometries. While four-dimensional on large scales, the quantum universe appears two-dimensional…

High Energy Physics - Theory · Physics 2010-04-06 J. Ambjorn , J. Jurkiewicz , R. Loll

We review recent developments in the understanding of the fractal properties of quantum spacetime of 2d gravity coupled to c>0 conformal matter. In particular we discuss bounds put by numerical simulations using dynamical triangulations on…

High Energy Physics - Lattice · Physics 2009-10-30 J. Ambjorn , K. N. Anagnostopoulos , G. Thorleifsson

We study a c=-2 conformal field theory coupled to two-dimensional quantum gravity by means of dynamical triangulations. We define the geodesic distance r on the triangulated surface with N triangles, and show that dim[r^{d_H}]= dim[N],…

High Energy Physics - Lattice · Physics 2019-08-15 J. Ambjorn , K. N. Anagnostopoulos , T. Ichihara , L. Jensen , N. Kawamoto , Y. Watabiki , K. Yotsuji

In various theories of quantum gravity, one observes a change in the spectral dimension from the topological spatial dimension $d$ at large length scales to some smaller value at small, Planckian scales. While the origin of such a flow is…

High Energy Physics - Theory · Physics 2015-04-22 Gianluca Calcagni , Daniele Oriti , Johannes Thürigen

We show that the ``time'' t_s defined via spin clusters in the Ising model coupled to 2d gravity leads to a fractal dimension d_h(s) = 6 of space-time at the critical point, as advocated by Ishibashi and Kawai. In the unmagnetized phase,…

High Energy Physics - Theory · Physics 2009-10-31 J. Ambjorn , K. N. Anagnostopoulos , J. Jurkiewicz , C. Kristjansen

An important probe of quantum geometry is its spectral dimension, defined via a spatial diffusion process. In this work we study the spectral dimension of a ``spatial hypersurface'' in a manifoldlike causal set using the induced spatial…

General Relativity and Quantum Cosmology · Physics 2020-01-08 Astrid Eichhorn , Sumati Surya , Fleur Versteegen

The so-called spectral dimension is a scale-dependent number associated with both geometries and field theories that has recently attracted much attention, driven largely though not exclusively by investigations of causal dynamical…

High Energy Physics - Theory · Physics 2011-12-12 Thomas P. Sotiriou , Matt Visser , Silke Weinfurtner

In this work we study the spectral dimensionality of spacetime around a radiating Schwarzschild black hole using a recently introduced formalism of quantum gravity, where the alterations of the gravitational field produced by the radiation…

General Relativity and Quantum Cosmology · Physics 2025-05-07 Mauricio Bellini , Juan Ignacio Musmarra , Pablo Alejandro Sanchez , Alan Sebastian Morales

Using Monte Carlo simulations we study the distributions of the 3-block mass $N_3$ in 4d, 5d, and 6d percolation systems. Because the probability of creating large 3-blocks in these dimensions is very small, we use a ``go with the winners''…

Disordered Systems and Neural Networks · Physics 2009-11-07 Gerald Paul , H. Eugene Stanley

The spectral dimension is an indicator of geometry and topology of spacetime and a tool to compare the description of quantum geometry in various approaches to quantum gravity. This is possible because it can be defined not only on smooth…

High Energy Physics - Theory · Physics 2014-06-19 Gianluca Calcagni , Daniele Oriti , Johannes Thürigen

We construct matter field theories in ``theory space'' that are fractal, and invariant under geometrical renormalization group (RG) transformations. We treat in detail complex scalars, and discuss issues related to fermions, chirality, and…

High Energy Physics - Theory · Physics 2008-11-26 Christopher T. Hill

We numerically perform a spectral analysis of a quasi-periodically driven spin 1/2 system, the spectrum of which is Singular Continuous. We compute fractal dimensions of spectral measures and discuss their connections with the time…

chao-dyn · Physics 2009-10-28 I. Guarneri , M. DiMeo

We show that in general a spacetime having a quantum group symmetry has also a scale dependent fractal dimension which deviates from its classical value at short scales, a phenomenon that resembles what observed in some approaches to…

High Energy Physics - Theory · Physics 2009-04-08 Dario Benedetti

The generalised spectral dimension $D_{ S}(T)$ provides a powerful tool for comparing different approaches to quantum gravity. In this work, we apply this formalism to the classical spectral actions obtained within the framework of…

High Energy Physics - Theory · Physics 2015-06-23 Natalia Alkofer , Frank Saueressig , Omar Zanusso

Causal Dynamical Triangulations (CDT) provide a non-perturbative formulation of Quantum Gravity assuming the existence of a global time foliation. In our earlier study we analyzed the effect of including $d$ copies of a massless scalar…

General Relativity and Quantum Cosmology · Physics 2015-04-15 Jan Ambjørn , Andrzej Görlich , Jerzy Jurkiewicz , Hongguang Zhang

We present a model of (modified) gravity on spacetimes with fractal structure based on packing of spheres, which are (Euclidean) variants of the Packed Swiss Cheese Cosmology models. As the action functional for gravity we consider the…

General Relativity and Quantum Cosmology · Physics 2016-05-25 Adam Ball , Matilde Marcolli

We consider a cosmological model starting from (1) the(1+3+6)-dimensional space-times consisting of the outer space (the 3-dimensional expanding section) and the inner space (the 6-dimensional section) and reaching (2) the Friedmann model…

General Relativity and Quantum Cosmology · Physics 2015-12-24 Kenji Tomita