Divergences and Orientation in Spinfoams

Abstract

We suggest that large radiative corrections appearing in the spinfoam framework might be tied to the implicit sum over orientations. Specifically, we show that in a suitably simplified context the characteristic "spike" divergence of the Ponzano-Regge model disappears when restricting the theory to just one of the two orientations appearing in the asymptotic limit of the vertex amplitude.

10 pages, 5 figures

References in corpus (11)

• Lorentzian spin foam amplitudes: graphical calculus and asymptotics
• Ponzano-Regge model revisited I: Gauge fixing, observables and interacting spinning particles
• Diffeomorphisms and spin foam models
• The Ponzano-Regge model
• Diffeomorphisms in group field theories
• 4-dimensional Spin-foam Model with Quantum Lorentz Group
• Quantum deformation of two four-dimensional spin foam models
• Breaking and restoring of diffeomorphism symmetry in discrete gravity
• Discrete Symmetries in Covariant LQG
• The Plebanski sectors of the EPRL vertex
• How to detect an anti-spacetime

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• A spin-foam vertex amplitude with the correct semiclassical limit
• Discretization independence implies non-locality in 4D discrete quantum gravity
• Pachner moves in a 4d Riemannian holomorphic Spin Foam model
• Dirac's discrete hypersurface deformation algebras
• Quasi-local holographic dualities in non-perturbative 3d quantum gravity II - From coherent quantum boundaries to BMS3 characters
• 3D holography: from discretum to continuum
• Quantization of systems with temporally varying discretization II: Local evolution moves
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• Quantum geometry from higher gauge theory
• The Lorentzian proper vertex amplitude: Classical analysis and quantum derivation
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• Quantum edge modes in 3d gravity and 2+1d topological phases of matter
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• Hessian and graviton propagator of the proper vertex
• Causal structure and topology change in (2+1)-dimensional simplicial gravity
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