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Related papers: Spin Foam Models

200 papers

We introduce a new basis on the state space of non-perturbative quantum gravity. The states of this basis are linearly independent, are well defined in both the loop representation and the connection representation, and are labeled by a…

General Relativity and Quantum Cosmology · Physics 2009-10-28 Carlo Rovelli , Lee Smolin

This document is on considerations and findings on modelling of spinning beams. Spinning has been proposed for stabilizing beams against perturbations notably risen by non-linear space charge forces, see [Y.-L. Cheon et al., Effects of beam…

Accelerator Physics · Physics 2024-08-16 L. Groening

We examine the four dimensional path integral for Euclidean quantum gravity in the context of the EPRL-FK spin foam model. The state sum is restricted to certain symmetric configurations which resembles the geometry of a flat homogeneous…

General Relativity and Quantum Cosmology · Physics 2017-10-25 Benjamin Bahr , Sebastian Kloser , Giovanni Rabuffo

Spin networks appear in a number of areas, for instance in lattice gauge theories and in quantum gravity. They describe the contraction of intertwiners according to the underlying network. We show that a certain generating function of…

General Relativity and Quantum Cosmology · Physics 2015-11-24 Bianca Dittrich , Jeff Hnybida

We find all the spin-foams contributing in the first order of the vertex expansion to the transition amplitude of the Bianchi-Rovelli-Vidotto Dipole Cosmology model. Our algorithm is general and provides spin-foams of arbitrarily given,…

General Relativity and Quantum Cosmology · Physics 2015-06-04 Marcin Kisielowski , Jerzy Lewandowski , Jacek Puchta

In the context of the coarse-graining of loop quantum gravity, we introduce loopy and tagged spin networks, which generalize the standard spin network states to account explicitly for non-trivial curvature and torsion. Both structures relax…

General Relativity and Quantum Cosmology · Physics 2016-08-11 Christoph Charles , Etera R. Livine

BF theory is a topological theory that can be seen as a natural generalization of 3-dimensional gravity to arbitrary dimensions. Here we show that the coupling to point particles that is natural in three dimensions generalizes in a direct…

General Relativity and Quantum Cosmology · Physics 2008-11-26 John C. Baez , Alejandro Perez

Any ensemble of quantum particles exhibits statistical fluctuations known as spin noise. Here, we provide a description of spin noise in the language of open quantum systems. The description unifies the signatures of spin noise under both…

Quantum Physics · Physics 2015-03-04 R. Annabestani , D. G. Cory , J. Emerson

We revise imposition of various constraints in spin foam models of 4-dimensional general relativity. We argue that the usual simplicity constraint must be supplemented by a constraint on holonomies and together they must be inserted…

General Relativity and Quantum Cosmology · Physics 2008-11-26 Sergei Alexandrov

We present a new group field theory model, generalising the Boulatov model, which incorporates both 3-dimensional gravity and matter coupled to gravity. We show that the Feynman diagram amplitudes of this model are given by Riemannian…

General Relativity and Quantum Cosmology · Physics 2007-05-23 Laurent Freidel , Daniele Oriti , James Ryan

We study the coupling of massive fermions to the quantum mechanical dynamics of spacetime emerging from the spinfoam approach in three dimensions. We first recall the classical theory before constructing a spinfoam model of quantum gravity…

General Relativity and Quantum Cosmology · Physics 2008-11-26 Winston Fairbairn

Group field theories whose Feynman diagrams describe 3d gravity with a varying configuration of Wilson loop observables and 3d gravity with volume observables at each vertex are defined. The volume observables are created by the usual spin…

General Relativity and Quantum Cosmology · Physics 2011-05-19 R. J. Dowdall

We develop a numerical method to investigate the semiclassical limit of spin foam amplitudes with many vertices. We test it using the Ponzano-Regge model, a spin foam model for three-dimensional euclidean gravity, and a transition amplitude…

General Relativity and Quantum Cosmology · Physics 2024-02-27 Pietro Dona , Francesco Gozzini , Giorgio Sarno

We show how super BF theory in any dimension can be quantized as a spin foam model, generalizing the situation for ordinary BF theory. This is a first step toward quantizing supergravity theories. We investigate in particular 3-dimensional…

High Energy Physics - Theory · Physics 2018-01-24 Etera R. Livine , Robert Oeckl

Spin Foam Models are supposed to be discretised path integrals for quantum gravity constructed from the Plebanski-Holst action. The reason for there being several models currently under consideration is that no consensus has been reached…

General Relativity and Quantum Cosmology · Physics 2013-11-01 Muxin Han , Thomas Thiemann

Plasma physics give an example of physical system of particles with the long range interaction. At small velocity of particles we can consider the plasma approximately as a system of particles with the Coulomb interaction. The Coulomb…

Plasma Physics · Physics 2015-04-10 P. A. Andreev

The evaluation of relativistic spin networks plays a fundamental role in the Barrett-Crane state sum model of Lorentzian quantum gravity in 4 dimensions. A relativistic spin network is a graph labelled by unitary irreducible representations…

General Relativity and Quantum Cosmology · Physics 2009-11-07 John C. Baez , John W. Barrett

In this and the companion paper a novel holonomy formulation of so called Spin Foam models of lattice gauge gravity are explored. After giving a natural basis for the space of simplicity constraints we define a universal boundary Hilbert…

General Relativity and Quantum Cosmology · Physics 2015-06-11 Bianca Dittrich , Frank Hellmann , Wojciech Kaminski

It has been shown in [1] that a class of restricted spin foam models can feature a reduced spectral dimension of space-time. However, it is still an open question how curvature affects the flow of the spectral dimension. To answer this…

General Relativity and Quantum Cosmology · Physics 2023-09-18 Alexander Jercher , Sebastian Steinhaus , Johannes Thürigen

We derive simplicity constraints for the quantization of general Lorentzian 4-geometries. Our method is based on the correspondence between coherent states and classical bivectors and the minimization of associated uncertainties. For…

General Relativity and Quantum Cosmology · Physics 2011-01-19 Florian Conrady , Jeff Hnybida