Integrability for Relativistic Spin Networks

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 of the Lorentz group appearing in the direct integral decom...

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Main Authors: Barrett, John W., Baez, John C.
Format: Article
Published: 2001
Online Access:https://eprints.nottingham.ac.uk/7/
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author Barrett, John W.
Baez, John C.
author_facet Barrett, John W.
Baez, John C.
author_sort Barrett, John W.
building Nottingham Research Data Repository
collection Online Access
description 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 of the Lorentz group appearing in the direct integral decomposition of the space of L^2 functions on three-dimensional hyperbolic space. To `evaluate' such a spin network we must do an integral; if this integral converges we say the spin network is `integrable'. Here we show that a large class of relativistic spin networks are integrable, including any whose underlying graph is the 4-simplex (the complete graph on 5 vertices). This proves a conjecture of Barrett and Crane, whose validity is required for the convergence of their state sum model.
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spelling nottingham-72020-05-04T20:32:38Z https://eprints.nottingham.ac.uk/7/ Integrability for Relativistic Spin Networks Barrett, John W. Baez, John C. 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 of the Lorentz group appearing in the direct integral decomposition of the space of L^2 functions on three-dimensional hyperbolic space. To `evaluate' such a spin network we must do an integral; if this integral converges we say the spin network is `integrable'. Here we show that a large class of relativistic spin networks are integrable, including any whose underlying graph is the 4-simplex (the complete graph on 5 vertices). This proves a conjecture of Barrett and Crane, whose validity is required for the convergence of their state sum model. 2001 Article NonPeerReviewed Barrett, John W. and Baez, John C. (2001) Integrability for Relativistic Spin Networks. Classical and Quantum Gravity, 18 (4683-4).
spellingShingle Barrett, John W.
Baez, John C.
Integrability for Relativistic Spin Networks
title Integrability for Relativistic Spin Networks
title_full Integrability for Relativistic Spin Networks
title_fullStr Integrability for Relativistic Spin Networks
title_full_unstemmed Integrability for Relativistic Spin Networks
title_short Integrability for Relativistic Spin Networks
title_sort integrability for relativistic spin networks
url https://eprints.nottingham.ac.uk/7/