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The Spin-Foam Approach to Quantum Gravity [PDF]
Living Reviews in Relativity, 2013 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.
Alejandro Perez
doaj +11 more sources
Spin Foams and Canonical Quantization [PDF]
Symmetry, Integrability and Geometry: Methods and Applications, 2012 This review is devoted to the analysis of the mutual consistency of the spin foam and canonical loop quantizations in three and four spacetime dimensions.
Sergei Alexandrov +2 more
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How-to Compute EPRL Spin Foam Amplitudes [PDF]
Universe, 2022 Spin foam theory is a concrete framework for quantum gravity where numerical calculations of transition amplitudes are possible. Recently, the field became very active, but the entry barrier is steep, mainly because of its unusual language and notions ...
Pietro Donà, Pietropaolo Frisoni
doaj +4 more sources
The Hessian in Spin Foam Models [PDF]
Annales Henri Poincaré, 2019 We fill one of the remaining gaps in the asymptotic analysis of the vertex amplitudes of the Engle–Pereira–Rovelli–Livine (EPRL) spin foam models: We show that the Hessian is nondegenerate for the stationary points that corresponds to geometric ...
W. Kamiński, H. Sahlmann
semanticscholar +5 more sources
Numerical evaluation of spin foam amplitudes beyond simplices [PDF]
Physical Review D, 2022 We present the first numerical calculation of the 4D Euclidean spin foam vertex amplitude for vertices with hypercubic combinatorics. Concretely, we compute the amplitude for coherent boundary data peaked on cuboid and frustum shapes.
C. Allen, F. Girelli, S. Steinhaus
semanticscholar +5 more sources
Coarse Graining Spin Foam Quantum Gravity—A Review [PDF]
Frontiers in Physics, 2020 In quantum gravity, we envision renormalization as the key tool for bridging the gap between microscopic models and observable scales. For spin foam quantum gravity, which is defined on a discretization akin to lattice gauge theories, the goal is to ...
Sebastian Steinhaus
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A spin foam framework for the black-to-white hole transition [PDF]
The Sixteenth Marcel Grossmann Meeting, 2021 Black holes formation and evolution have been extensively studied at the classical level. However, not much is known regarding the end of their lives, a phase that requires to consider the quantum nature of the gravitational field.
Farshid Soltani
semanticscholar +2 more sources
Spin Foam Models from the Tetrad Integration [PDF]
, 2006 We describe a class of spin foam models of four-dimensional quantum gravity which is based on the integration of the tetrad one-forms in the path integral for the Palatini action of General Relativity.
Aleksandar Miković
core +9 more sources
Spin angular momentum modulation via spin–orbit interaction in fractional orbital angular momentum beams [PDF]
NanophotonicsLight exhibits both spin and orbital angular momentum (SAM and OAM). These two forms of angular momentum remain independent in paraxial fields, but become coupled in confined fields through spin–orbit interactions (SOI).
Chen Xusheng +4 more
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4-dimensional spin-foam model with quantum Lorentz group [PDF]
, 2011 We study the quantum group deformation of the Lorentzian EPRL spin-foam model. The construction uses the harmonic analysis on the quantum Lorentz group.
Muxin Han
openalex +5 more sources