Tensorial Structure of the LQG graviton propagator

Abstract

We review the construction of the tensorial structure of the graviton propagator in the context of loop quantum gravity and spinfoam formalism. The main result of this analysis is that applying the same strategy used to compute the diagonal terms, the Barrett-Crane vertex is unable to yield the correct propagator in the long distance limit. The problem is in the intertwiner-independence of the Barrett-Crane vertex. We also review the asymptotic behavior of an alternative vertex that is able to give the correct propagator.

arXiv comment4 pages,; to appear in the proceedings of the II Stueckelberg Workshop, Int.J.Mod.Phys.A

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• Asymptotics of LQG fusion coefficients
• Semi-Classical Holomorphic Transition Amplitudes in Covariant Loop Quantum Gravity