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Related papers: EPRL/FK Asymptotics and the Flatness Problem

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The goal of spin foam models is to provide a viable path integral formulation of quantum gravity. Because of background independence, their underlying framework has certain novel features that are not shared by path integral formulations of…

General Relativity and Quantum Cosmology · Physics 2011-01-25 Abhay Ashtekar , Miguel Campiglia , Adam Henderson

Spin foam models are an attempt for a covariant, or path integral formulation of canonical loop quantum gravity. The construction of such models usually rely on the Plebanski formulation of general relativity as a constrained BF theory and…

General Relativity and Quantum Cosmology · Physics 2015-05-13 Aristide Baratin , Cecilia Flori , Thomas Thiemann

We study the behavior of holonomy spin foam partition functions, a form of lattice gauge gravity, on generic 4d-triangulations using micro local analysis. To do so we adapt tools from the renormalization theory of quantum field theory on…

General Relativity and Quantum Cosmology · Physics 2012-10-22 Frank Hellmann , Wojciech Kaminski

The Spin Foam approach to quantum gravity aims at providing a covariant path-integral formulation of canonical Loop Quantum Gravity. Since spin foam amplitudes are defined through discretisations of spacetime, understanding the continuum…

General Relativity and Quantum Cosmology · Physics 2026-03-19 Matteo Bruno , Eugenia Colafranceschi , Fabio M. Mele , Carlo Rovelli

We give a general definition of spin foam models, and then of models of 4d quantum gravity based on constraining BF theory. We highlight the construction and quantization ambiguities entering model building, among which the choice of…

General Relativity and Quantum Cosmology · Physics 2019-06-19 Marco Finocchiaro , Daniele Oriti

In previous work, the Lorentzian proper vertex amplitude for a spin-foam model of quantum gravity was derived. In the present work, the asymptotics of this amplitude are studied in the semi-classical limit. The starting point of the…

General Relativity and Quantum Cosmology · Physics 2016-09-14 Jonathan Engle , Ilya Vilensky , Antonia Zipfel

This article reviews the present status of the spin foam approach to the quantization of gravity. Special attention is payed to the pedagogical presentation of the recently introduced new models for four dimensional quantum gravity. The…

General Relativity and Quantum Cosmology · Physics 2015-06-05 Alejandro Perez

We study perturbation theory for spin foam models on triangulated manifolds. Starting with any model of this sort, we consider an arbitrary perturbation of the vertex amplitudes, and write the evolution operators of the perturbed model as…

General Relativity and Quantum Cosmology · Physics 2023-03-07 John C. Baez

In this article we consider physical states in the hypercuboidal truncation of the EPRL-FK spin foam quantum gravity model. In particular, these states are defined on graphs which allow considering the entanglement entropy (EE) associated…

General Relativity and Quantum Cosmology · Physics 2020-06-17 Benjamin Bahr

In this thesis we study the flat model, the main buidling block for the spinfoam approach to quantum gravity, with an emphasis on its divergences. Besides a personal introduction to the problem of quantum gravity, the manuscript consists in…

General Relativity and Quantum Cosmology · Physics 2012-01-25 Matteo Smerlak

Spin foam models for quantum gravity are derived from lattice path integrals. The setting involves variables from both lattice BF theory and Regge calculus. The action consists in a Regge action, which depends on areas, dihedral angles and…

General Relativity and Quantum Cosmology · Physics 2013-05-29 Valentin Bonzom

Spin foams are candidate state-sum models for transition amplitudes in quantum gravity. An active research subject is to identify the possible divergences of spin foam models, or alternatively to show that models are finite. We will discuss…

General Relativity and Quantum Cosmology · Physics 2013-12-16 Valentin Bonzom , Bianca Dittrich

We describe how a spin-foam state sum model can be reformulated as a quantum field theory of spin networks, such that the Feynman diagrams of that field theory are the spin-foam amplitudes. In the case of open spin networks, we obtain a new…

General Relativity and Quantum Cosmology · Physics 2009-11-07 A. Mikovic

The graphical calculus method is generalized to study the relation between covariant and canonical dynamics of loop quantum gravity. On one hand, a graphical derivation of the partition function of the generalized Euclidean…

General Relativity and Quantum Cosmology · Physics 2021-08-17 Jinsong Yang , Cong Zhang , Yongge Ma

We propose a way to describe the origin of black hole entropy in the spin foam models of quantum gravity. This stimulates a new way to study the relation of spin foam models and loop quantum gravity.

General Relativity and Quantum Cosmology · Physics 2008-11-26 J. Manuel Garcia-Islas

We review aspects of loop quantum gravity and spin foam models at an introductory level, with special attention to questions frequently asked by non-specialists.

High Energy Physics - Theory · Physics 2008-11-26 Hermann Nicolai , Kasper Peeters

We derive the the Barrett-Crane spin foam model for Euclidean 4 dimensional quantum gravity from a discretized BF theory, imposing the constraints that reduce it to gravity at the quantum level. We obtain in this way a precise prescription…

General Relativity and Quantum Cosmology · Physics 2009-10-31 Daniele Oriti , Ruth M. Williams

Spinfoams provide a framework for the dynamics of loop quantum gravity that is manifestly covariant under the full four-dimensional diffeomorphism symmetry group of general relativity. In this way they complete the ideal of…

General Relativity and Quantum Cosmology · Physics 2023-11-01 Jonathan Engle , Simone Speziale

In this paper, we address the problem of the dynamics in three dimensional loop quantum gravity with zero cosmological constant. We construct a rigorous definition of Rovelli's generalized projection operator from the kinematical Hilbert…

General Relativity and Quantum Cosmology · Physics 2009-11-10 Karim Noui , Alejandro Perez

We show how Feynman amplitudes of standard QFT on flat and homogeneous space can naturally be recast as the evaluation of observables for a specific spin foam model, which provides dynamics for the background geometry. We identify the…

High Energy Physics - Theory · Physics 2008-11-26 Aristide Baratin , Laurent Freidel