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Matrix model formulation of four dimensional gravity [PDF]

Nucl.Phys.Proc.Suppl. 94 (2001) 697-700, 2000
The attempt of extending to higher dimensions the matrix model formulation of two-dimensional quantum gravity leads to the consideration of higher rank tensor models. We discuss how these models relate to four dimensional quantum gravity and the precise conditions allowing to associate a four-dimensional simplicial manifold to Feynman diagrams of a ...
Ambjorn, Barrett, Boulatov, Boulatov, De Pietri, De Pietri, Ooguri, Ponzano, Roberto De Pietri   +8 more
arxiv   +5 more sources

Quantum gravity as a group field theory: a sketch [PDF]

J.Phys.Conf.Ser. 33 (2006) 271-278, 2005
We give a very brief introduction to the group field theory approach to quantum gravity, a generalisation of matrix models for 2-dimensional quantum gravity to higher dimension, that has emerged recently from research in spin foam models.
A Perez C Rovelli, Baratin A, D Oriti editor, Daniele Oriti, Freidel L, Freidel L, Freidel L, Halliwell J J, Krasnov K, Morozov A, Oriti D, Oriti D, Oriti D, Perez A   +13 more
arxiv   +3 more sources

A New Class of Group Field Theories for 1st Order Discrete Quantum Gravity [PDF]

Class.Quant.Grav.25:085011,2008, 2007
Group Field Theories, a generalization of matrix models for 2d gravity, represent a 2nd quantization of both loop quantum gravity and simplicial quantum gravity. In this paper, we construct a new class of Group Field Theory models, for any choice of spacetime dimension and signature, whose Feynman amplitudes are given by path integrals for clearly ...
Baez J C, Barrett J W, D Oriti, Engle J Pereira R Rovelli C, Freidel L, Freidel L, Freidel L Krasnov K, Freidel L Krasnov K Oriti D, Gelfand I M, Gradshteyn I S, Hamber H W, Hermann R, Livine E Speziale S, Oriti D, Oriti D, Oriti D, Oriti D, Perez A, Perez A Bojowald M, Reisenberger M, Rivers R J, Rovelli C, T Tlas, Williams R   +23 more
arxiv   +3 more sources

Quantum gravity and the standard model [PDF]

Classical and Quantum Gravity, 2007
12 pages, 21 figures, improved presentation, results ...
Sundance Bilson-Thompson, Fotini Markopoulou, Lee Smolin   +2 more
openalex   +5 more sources

Testing A (Stringy) Model of Quantum Gravity [PDF]

, 2000
I discuss a specific model of space-time foam, inspired by the modern non-perturbative approach to string theory (D-branes). The model views our world as a three brane, intersecting with D-particles that represent stringy quantum gravity effects, which can be real or virtual.
Nick E. Mavromatos
openalex   +5 more sources

SPIN FOAM MODELS OF QUANTUM GRAVITY [PDF]

Mathematical, Theoretical and Phenomenological Challenges Beyond the Standard Model, 2005
We give a short review of the spin foam models of quantum gravity, with an emphasis on the Barret-Crane model. After explaining the shortcomings of the Barret-Crane model, we briefly discuss two new approaches, one based on the 3d spin foam state sum invariants for the embedded spin networks, and the other based on representing the string scattering ...
Aleksandar Miković
openalex   +5 more sources

Gravitational Decoherence [PDF]

Class. Quantum Grav. 34, 193002 (2017), 2017
We discuss effects of loss of coherence in low energy quantum systems caused by or related to gravitation, referred to as gravitational decoherence. These effects, resulting from random metric fluctuations, for instance, promise to be accessible by relatively inexpensive table-top experiments, way before the scales where true quantum gravity effects ...
Bassi, Angelo, Großardt, André, Ulbricht, Hendrik   +2 more
arxiv   +22 more sources

Contextual extensions of quantum gravity models [PDF]

International Journal of Geometric Methods in Modern Physics Vol. 18, No. 6 (2021) 2150085, 2020
We present a simple way of incorporating the structure of contextual extensions into quantum gravity models. The contextual extensions of $C^*$-algebras, originally proposed for contextual hidden variables, are generalized to the cones indexed by the contexts and their limit in a category. By abstracting the quantum gravity models as functors, we study
arxiv   +5 more sources

State sum models for quantum gravity [PDF]

, 2000
amslatex, 7 pages, ICMP conference ...
John W. Barrett
openalex   +5 more sources

Analogue model for quantum gravity phenomenology [PDF]

Journal of Physics A: Mathematical and General, 2006
So called "analogue models" use condensed matter systems (typically hydrodynamic) to set up an "effective metric" and to model curved-space quantum field theory in a physical system where all the microscopic degrees of freedom are well understood. Known analogue models typically lead to massless minimally coupled scalar fields.
Silke Weinfurtner, Stefano Liberati, Matt Visser   +2 more
openalex   +5 more sources