Towards spinfoam cosmology

By Eugenio Bianchi, Carlo Rovelli, F. Vidotto. 2010

152 citations recorded by the source corpus.

We compute the transition amplitude between coherent quantum states of geometry peaked on homogeneous-isotropic metrics. We work in the context of pure gravity without matter, we use the holomorphic representations of loop quantum gravity and the Kaminski-Kisielowski-Lewandowski generalization of the new vertex, and work at first order in the vertex expansion, second order in the graph (multipole) expansion, and first order in volume{sup -1}. We show that the resulting amplitude is in the kernel of a differential operator whose classical limit is the canonical Hamiltonian of a Friedmann-Robertson-Walker cosmology. This result is an indication that the dynamics of loop quantum gravity defined by the new vertex reproduces the gravity part of the Friedmann equation in the appropriate limit.

Subfields: Atomic and Molecular Physics, and Optics, Nuclear and High Energy Physics, Statistical and Nonlinear Physics

View Paper: https://www.semanticscholar.org/paper/06cf9ae2858a58c86be0c8cb33830cf4c3678b2c

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Citations in the corpus

Homogeneous cosmologies as group field theory condensates (2013, background): “Following recent work [45, 46], we call ξ a ‘dipole’ function on the gauge-invariant configuration space of a single tetrahedron.”
Zakopane lectures on loop gravity (2011, background): “Compute the cosmological transition amplitude in the Lorentzian theory, extending the euclidean result of [102].”
Introduction to Loop Quantum Cosmology (2011, background): “Another possibility, also dubbed “spin-foam cosmology” and attempting to get in closer contact with the full theory, is to evaluate spin-foam amplitudes on graphs interpreted as homogeneous and isotropic geometries [36, 37, 115, 134, 168, 193, 194].”
Loop quantum cosmology: a status report (2011, methodology): “[107] E.”
Polyhedra in loop quantum gravity (2010, background): “This truncation provides a useful computational tool, to be compared to a perturbative expansion, and has found many applications, from the study of propagators [37] to cosmology [38].”
The Spin-Foam Approach to Quantum Gravity (2012, background): “6 Spin-foam cosmology The spin-foam approach applied to quantum cosmology has been explored in [74, 366, 222, 79, 335, 334].”
A new look at loop quantum gravity (2010, background): “(10) Is there any reason for a breaking or a deformation of local Lorentz invariance, that could lead to observable phenomena such as γ ray bursts energy-dependent time of arrival delays, in this theory? (11) Compute the cosmological transition amplitude in the Lorentzian theory, extending the Eucli”
Emergent Friedmann dynamics with a quantum bounce from quantum gravity condensates (2016, background): “[47] E.”
Loop Quantum Gravity (2003, methodology): “For instance, in a cosmological context, the transition amplitudes have been used to directly compute the quantum evolution of a “universe”, meaning the large scale modes of a compact geometry [39].”