Curvature in spinfoams

Abstract

We consider spinfoam quantum gravity. We show in a simple case that the amplitude projects over a nontrivial (curved) classical geometry. This suggests that, at least for spinfoams without bubbles and for large values of the boundary spins, the amplitude takes the form of a path integral over Regge metrics, thus enforcing discrete Einstein equations in the classical limit. The result relies crucially on a new interpretation of the semiclassical limit for the amplitudes truncated to a fixed 2-complex.

7 pages, 3 figures

References in corpus (12)

• LQG vertex with finite Immirzi parameter
• A new spinfoam vertex for quantum gravity
• A New Spin Foam Model for 4d Gravity
• Towards Spinfoam Cosmology
• The complete LQG propagator: I. Difficulties with the Barrett-Crane vertex
• Area-angle variables for general relativity
• EPRL/FK Group Field Theory
• Loop quantum gravity: the first twenty five years
• Lorentz covariance of loop quantum gravity
• Quantum Corrections in the Group Field Theory Formulation of the EPRL/FK Models
• Coarse graining free theories with gauge symmetries: the linearized case
• Spinfoam fermions

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• Addendum: EPRL/FK Asymptotics and the Flatness Problem
• EPRL/FK Asymptotics and the Flatness Problem
• Spin-foams as semi-classical vertices: gluing constraints and a hybrid algorithm
• On the structure of a background independent quantum theory: Hamilton function, transition amplitudes, classical limit and continuous limit
• Semi-Classical Holomorphic Transition Amplitudes in Covariant Loop Quantum Gravity