Local spinfoam expansion in loop quantum cosmology

Abstract

The quantum dynamics of the flat Friedmann-Lemaitre-Robertson-Walker and Bianchi I models defined by loop quantum cosmology have recently been translated into a spinfoam-like formalism. The construction is facilitated by the presence of a massless scalar field which is used as an internal clock. The implicit integration over the matter variable leads to a nonlocal spinfoam amplitude. In this paper we consider a vacuum Bianchi I universe and show that by choosing an appropriate regulator a spinfoam expansion can be obtained without selecting a clock variable and that the resulting spinfoam amplitude is local.

12 pages

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• Many-nodes/many-links spinfoam: the homogeneous and isotropic case
• Loop Quantum Gravity
• Classical Setting and Effective Dynamics for Spinfoam Cosmology
• Observations in Quantum Cosmology
• Semiclassical Limit of New Path Integral Formulation from Reduced Phase Space Loop Quantum Gravity
• Coherent State Functional Integral in Loop Quantum Cosmology: Alternative Dynamics
• Discretisations, Constraints and Diffeomorphisms in Quantum Gravity
• Path Integrals and Alternative Effective Dynamics in Loop Quantum Cosmology
• Two-point functions in (loop) quantum cosmology
• Observations on interfacing loop quantum gravity with cosmology
• Coherent State Functional Integrals in Quantum Cosmology
• Hamiltonian spinfoam gravity
• Spin-foam model for gravity coupled to massless scalar field
• Diffeomorphism invariant cosmological sector in loop quantum gravity
• The consistent histories approach to loop quantum cosmology
• Spinfoams: Foundations
• Toward matter dynamics in spin foam quantum gravity
• Causal structure in spin-foams
• Cosmological dynamics in spin-foam loop quantum cosmology: challenges and prospects